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Sample records for didelphys blind hemivagina

  1. Ectopic ureter associated with uterine didelphys and obstructed hemivagina: preoperative diagnosis by MRI.

    PubMed

    Wang, Zhen J; Daldrup-Link, Heike; Coakley, Fergus V; Yeh, Benjamin M

    2010-03-01

    Uterine didelphys with obstructed hemivagina and ipsilateral renal anomalies is a rare congenital malformation of the female urogenital tract. While the urinary anomalies almost always involve renal agenesis, we report a rare case of a 17-year-old girl with the malformation associated with ectopic ureteral insertion into the obstructed hemivagina, which was diagnosed preoperatively by MR imaging. To the best of our knowledge, preoperative MR imaging diagnosis of the ectopic ureter associated with this syndrome has not been previously reported. Accurate preoperative diagnosis of ectopic ureteral insertion associated with this syndrome is important for surgical planning.

  2. Novel use of a tracheobronchial stent in a patient with uterine didelphys and obstructed hemivagina

    PubMed Central

    Cooper, Amber R.; Merritt, Diane F.

    2014-01-01

    Objective: To describe a novel use for a tracheobronchial stent to maintain patency after vaginal septum excision in a patient with an obstructed hemivagina and uterine didelphys. Design: Description of a novel technique Setting: University-affiliated Children’s Hospital Patient: One patient with an obstructed hemivagina and uterine didelphys who presented with hematometria and hematocolpos. Intervention: In order to maintain patency and decrease stenosis risk after vaginal septum excision, a coated tracheobronchial stent was deployed and left in place for 6 weeks. Main Outcome Measure: To evaluate ease of stent placement and removal, re-epithelialization and patency of the neo-vagina, and post-operative assessment of pain and recurrent obstruction. Results: The tracheobroncheal stent was easily positioned and deployed with vaginoscopic guidance. Six weeks later it was removed without any tissue in-growth or granulation tissue noted. The vaginal walls were nicely epithelialized. Twelve months post-operatively the patient remained pain free with regular cycles and no evidence of obstruction or abnormality on ultrasound. Conclusion: Use of a coated tracheobronchial stent to maintain patency after septum excision in a patient with an obstructed hemivagina presents a safe, easy and effective option to diminish stenosis risk and avoid infectious complications or hysterectomy. PMID:19064265

  3. [Obstructed hemivagina and ipsilateral renal anomaly: unusual cause of piocolpos. Report a case and review of literature ].

    PubMed

    Cortés-Contreras, Diana Karen; Juárez-Cruz, Patricio Manuel; Vázquez-Flores, José; Vázquez-Flores, Al David

    2014-10-01

    OHVIRA (Obstructed hemivagina and ipsilateral renal anomaly) by acronym and abbreviations in English or Herlyn Werner Wunderlich syndrome is a rare congenital malformation caused by an alteration in the Mullerian ducts and Wolffian Ducts. Which is characterized by a triad: uterus didelphys, obstructed and ipsilateral renal agenesis hemivagina still uncertain etiology. Patients are usually asymptomatic until menarche where the most common clinical presentation is pelvic pain, followed by a vaginal or abdominal mass, normal menstrual periods, infertility, and vaginal discharge rarely appears. The case of a female patient of 15 years, nubile with chronic fetid vaginal discharge, initially diagnosed and treated as pelvic inflammatory disease occurs, however because it is an exceptional condition with the background of the patient, by complementary studies were conducted where pelvic ultrasound revealed pyocolpos and absence of left kidney, uterus didelphys, blind hemivagina by other imaging studies, where we could integrate Herlyn-Werner-Wunderlich syndrome. In conclusion, abnormalities in the development of the Miillerian ducts are difficult to diagnose early, so you must have the embryological knowledge, conduct thorough clinical assessment and detailed picture in whom the coridition is suspected to identify malformations coexisting urinary tract and vaginal defects with the importance of preserving reproductive success through appropriate planning of surgical approach, given that the fertility rate in these patients is comparable to the average.

  4. Double uterus with obstructed hemivagina and ipsilateral renal agenesis: pelvic anatomic variants in 87 cases.

    PubMed

    Fedele, L; Motta, F; Frontino, G; Restelli, E; Bianchi, S

    2013-06-01

    What are the anatomic variants (and their frequencies) of double uterus, obstructed hemivagina and ipsilateral renal agenesis? Most cases examined (72.4%) were of the classic anatomic variant of the Herlyn-Werner-Wunderlich syndrome (with didelphys uterus, obstructed hemivagina and ipsilateral renal agenesis) but the 27.6% of cases are of a rare variant of the syndrome (with uterus septum or cervical agenesis), showing relevant clinical and surgical implications. The extreme variability of anatomic structures involved in this syndrome (both uterus, cervico-vaginal and renal anomalies) is well known, even if a complete and uniform analysis of all its heterogeneous presentations in a large series is lacking. This is a retrospective study with 87 patients referred to our third level referral center between 1981 and 2011. We analyzed the laparoscopic and chart records of 87 women, who referred to our institute with double uterus, unilateral cervico-vaginal obstruction and ipsilateral renal anomalies. Sixty-three of 87 patients had the more classic variant of didelphys uterus with obstructed hemivagina; 10/87 patients had septate bicollis uterus with obstructed hemivagina; 9/87 patients had bicornuate bicollis uterus with obstructed hemivagina; 4/87 patients had didelphys uterus with unilateral cervical atresia; 1/87 patients had bicornuate uterus with one septate cervix and unilateral obstructed hemivagina. This is a retrospective study with a long enrolling period (30 years). New insights in the anatomic variants of this rare syndrome with their relevant surgical implications.

  5. [Müllerian anomalies. Obstructed hemivagina and ipsilateral renal anomaly syndrome (OHVIRA)].

    PubMed

    Afrashtehfar, Cyrus Dean Mario; Piña-García, Adrián; Afrashtehfar, Kelvin Ian

    2014-01-01

    Müllerian duct anomalies are a group of uncommon and underdiagnosed entities, which cause specific symptoms in adolescent females and may be associated with infertility as well as adverse pregnancy outcomes. These malformations occur as a result of an arrest or abnormal development of the Müllerian ducts in different stages of the female reproductive tract during gestation. Obstructed hemivagina and ipsilateral renal anomaly syndrome (OHVIRA), formerly known as the Herlyn-Werner-Wunderlich syndrome, is a rare entity characterized by the presence of a uterus didelphys with an obstructed hemivagina cause by a vaginal septum and the association of a renal anomaly (most commonly renal agenesis) ipsilateral to the obstruction. This syndrome may remain undiagnosed during childhood and usually becomes symptomatic after menarche, causing obstructive symptoms. Occasionally it may be identified after the evaluation of a patient with infertility or recurrent pregnancy loss. The clinical diagnosis is very challenging and requires imaging studies in which ultrasound and MRI play an essential role in the diagnosis, classification and treatment plan. Opportune diagnosis and treatment achieve complete improvement of symptoms, adequate reproductive prognosis and avoid major complications such as endometriosis, pelvic adhesions and infertility. The purpose of this review is to demonstrate the pathophysiology, clinical manifestations, diagnostic methods and treatment of the obstructed hemivagina and ipsilateral renal anomaly syndrome.

  6. Wolffian Origin of Vagina Unfolds the Embryopathogenesis of OHVIRA (Obstructed Hemivagina and Ipsilateral Renal Anomaly) Syndrome and Places OHVIRA as a Female Counterpart of Zinner Syndrome in Males

    PubMed Central

    Aswani, Yashant; Varma, Ravi; Choudhary, Pradeep; Gupta, Reeta B.

    2016-01-01

    Summary Background The classical theory of Müllerian origin of upper vagina fails to explain complex urogenital malformations like OHVIRA syndrome; the Acien’s hypothesis, however, unravels the hidden embryopathogenesis. As per Acien, Wolffian (mesonephric) ducts instead of Müllerian ducts and sinovaginal bulbs, give rise to the vagina. The new hypothesis, however, retains the concept of origin of the ureters (with ureters inducing renal development) by the former and the uterus by Müllerian ducts. Thus, a failure of development of mesonephros/mesonephric duct gives rise to absent ureters and hence absent homolateral kidney; blind ending (obstructed) ipsilateral hemivagina and cessation of support to paramesonephric ducts which leads to unfused uterus (uterus didelphys). Hence, the new hypothesis explains all components of OHVIRA syndrome. On a parallel track, unilateral anomalous development of the mesonephros in males causes atresia of the homolateral ejaculatory duct that results in obstruction of the proximally placed seminal vesicle. Besides, there is absence of the ipsilateral kidney (Zinner syndrome). Case Report In this manuscript, we describe four cases of OHVIRA syndrome. Case 1 was a 34-year-old nulligravida, married since fourteen years, who presented with a 5-month history of pelvic inflammatory disease and dyspareunia. Regular menses in the patient and azoospermia in her husband delayed the diagnosis. Case 2 was a 14-year-old girl who presented with dysmenorrhea and lower abdominal pain since a few months. Case 3 was a 27-year-old female who presented with infertility and dysmenorrhea. Case 4 was a 15-year-old female who presented with a one-year history of dysmenorrhea and cyclic pelvic pain. In all cases, one of the uterine horns revealed collection due to a hemivaginal septum and an absent ipsilateral kidney; thus, establishing the diagnosis of OHVIRA syndrome. The case 4 additionally revealed homolateral vaginal agenesis. Conclusions On the

  7. Successful laparoscopic transabdominal cerclage in uterus didelphys.

    PubMed

    Ades, Alex; Hong, Phoebe

    2015-11-17

    The incidence of uterus didelphys is around 3/10,000 women. It is a class III Müllerian duct anomaly resulting from a complete non-fusion of the paired Müllerian ducts between the 12th and 16th weeks of gestation. Although the prevalence of cervical insufficiency in women with uterus didelphys is unknown, the incidence of cervical insufficiency in women with Müllerian anomalies has been reported as high as 30%. We present a case of successful pregnancy outcome following a laparoscopic transabdominal cerclage in a woman with uterus didelphys and cervical insufficiency. The case demonstrates that laparoscopic transabdominal cerclage can be performed successfully in women with uterus didelphys and a satisfactory obstetric outcome can be achieved.

  8. Sonographic diagnosis of Obstructed Hemivagina and Ipsilateral Renal Anomaly Syndrome: a report of two cases

    PubMed Central

    Ng, Stanley

    2015-01-01

    Abstract Obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) syndrome is a rare urogenital anomaly. Patients typically present at puberty, shortly after menarche with increasing pelvic pain, dysmenorrhea and pelvic mass. There may be a known history of unilateral renal agenesis. Diagnosis can usually be established by ultrasound or magnetic resonance imaging. Resection of the vaginal septum is the treatment of choice. Early diagnosis and treatment can relieve symptoms, prevent complications and preserve fertility. We present two cases of OHVIRA syndrome diagnosed by ultrasound to promote recognition of this rare but important condition. PMID:28191231

  9. Blindness

    MedlinePlus

    ... CPR: A Real Lifesaver Kids Talk About: Coaches Blindness KidsHealth > For Kids > Blindness Print A A A ... help, are sometimes called "legally blind." What Causes Blindness? Vision problems can develop before a baby is ...

  10. Blindness

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    ... Emergency Room? What Happens in the Operating Room? Blindness KidsHealth > For Kids > Blindness A A A What's ... help, are sometimes called "legally blind." What Causes Blindness? Vision problems can develop before a baby is ...

  11. Blindness

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    ... visual function, preservation of sight, and the special health problems and requirements of the blind.” News & Events Events Calendar NEI Press Releases News from NEI Grantees Spokesperson bios Statistics and ... Frequently asked questions Clinical Studies Publications Catalog ...

  12. Superfetation in uterus pseudo didelphys: an unreported event.

    PubMed

    Singhal, Savita Rani; Agarwal, Umber; Sharma, Damyanti; Sen, Jyotsna

    2003-08-01

    A 20-year-old primigravida initially diagnosed at 28 weeks to have superfetation in a case of a bicornuate uterus was subsequently found to have uterus pseudo didelphys during a cesarean section at 35 weeks. This type of uterine anomaly with twin gestation has been previously reported in five case reports, but superfetation with such müllerian abnormality has not been previously described.

  13. Besnoitia darlingi infection in a Virginia opossum (Didelphis virginiana).

    PubMed

    Shaw, Shannon; Grasperge, Britton; Nevarez, Javier; Reed, Scott; Long, Lauren; Rademacher, Nathalie; Sánchez-Migallón Guzmán, David

    2009-03-01

    This is a case report of natural infection with Besnoitia darlingi in a Virginia opossum (Didelphis virginiana) in Louisiana. Clinical pathologic data included a severe nonregenerative anemia, inflammatory leukogram, increased hepatocellular leakage enzymes, renal azotemia, hyperkalemia, hypoglycemia, hypoalbuminemia, and proteinuria. Tissue cysts containing bradyzoites were found in the majority of organs, especially the skin, mucous membranes, kidneys, adrenals, lungs, and heart. Images of the bradyzoites obtained by transmission electron microscopy were consistent with the previously described ultrastructure of Besnoitia darlingi. This opossum also suffered from an open phalangeal fracture and concurrent gastrointestinal parasites. Histopathologic findings included a glomerulonephritis and hepatic necrosis.

  14. Use of 3-D MRI to Diagnose Unilateral Cervical Atresia in Obstructive Hemivagina with Ipsilateral Renal Anomaly (OHVIRA): A Case Report and Review of the Literature.

    PubMed

    Tomlin, Kristl; Barnes, Craig; Van Leeuwen, Kathy; Williamson, Amy

    2017-07-28

    Congenital atresia of the cervix in the setting of an obstructed hemivagina with ipsilateral renal anomaly (OHVIRA) is an unusual occurrence which is frequently missed by preoperative imaging modalities. A 14 year-old adolescent female presented to a tertiary-care facility with abdominal pain associated with a mass. Initial imaging with ultrasound and MRI (magnetic resonance imaging) suggested OHVIRA but a 3-D MRI also correctly identified unilateral cervical atresia on the obstructed left side. 3-D MRI in the setting of OHVIRA was used successfully in this case to preoperatively identify cervical atresia and to guide preoperative surgical counseling and planning. The use of 3-D MRI for this purpose has never been described in the literature. Copyright © 2017. Published by Elsevier Inc.

  15. Didelphis albiventris naturally infected with Hepatozoon canis in southeastern Brazil.

    PubMed

    da Silva, Maria Regina Lucas; Fornazari, Felipe; Demoner, Larissa de Castro; Teixeira, Carlos Roberto; Langoni, Helio; O'Dwyer, Lucia Helena

    2017-10-01

    Hepatozoon species are vector-borne pathogens that infect domestic and wild animals. Marsupials of the species Didelphis albiventris are adapted to urban and peri-urban areas and act as reservoir hosts for several parasites. The present study evaluated the occurrence of infection by Hepatozoon species in synantropic D. albiventris from Botucatu, São Paulo, Brazil. Blood samples and ectoparasites from 19 D. albiventris were collected from urban and peri-urban areas. Hepatozoon spp. detection was performed by microscopy and molecular analysis. One opossum was positive for Hepatozoon spp. in microscopy analysis and PCR, while another animal was positive only in PCR. The obtained sequences were 100% identical to Hepatozoon canis. Six species of ticks and two species of fleas were detected on D. albiventris. This is the first report of H. canis in synantropic D. albiventris. In Brazil, H. canis transmission among dog populations is not well established, which highlights the importance of investigating the role that opossums might play in the epidemiology of this protozoan. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Anatomical study of the opossum (Didelphis albiventris) extraocular muscles.

    PubMed Central

    Matheus, S M; Soares, J C; da Silva, A M; Seullner, G

    1995-01-01

    The anatomy of the extraocular muscles was studied in 10 adult opossums (Didelphis albiventris) of both sexes. Eight extraocular muscles were identified: 4 rectus muscles, 2 oblique muscles, the levator palpebrae superioris and the retractor ocular bulbi. The rectus muscles originate very close one to another between the orbital surfaces of the presphenoid and palatine bones. These muscles diverge on the way to their insertion which occurs at about 2 mm from the limbus. The levator palpebrae superioris originates with the dorsal rectus and is positioned dorsally in relation to it. The retractor ocular bulbi forms a cone which embraces the optic nerve and is located internally in relation to the rectus muscles. The dorsal oblique originates on the presphenoid bone and after a tendinous trajectory through a trochlea on the medial wall of the orbit, inserts into the ocular bulb. The only muscle arising from the anterior orbital floor is the ventral oblique. The main nerve supply for these muscles is the oculomotor, except for the dorsal oblique which is innervated by the trochlear nerve, and the lateral rectus which is innervated by the abducens nerve. The retractor ocular bulbi receives branches from the inferior division of the oculomotor nerve and some branches from the abducens nerve. Images Fig. 1 Fig. 2 Fig. 3 PMID:7649843

  17. Noncanalized horns of uterus didelphys with prolapse: a unique case in a young woman.

    PubMed

    Christopoulos, P; Deligeoroglou, E; Liapis, A; Agapitos, E; Papadias, K; Creatsas, G

    2009-01-01

    The authors report the unique case of a 20-year-old patient with prolapsed uterus didelphys with noncanalized horns, who complained of primary amenorrhea. Clinical examination revealed a rudimentary noncanalized cervix with a third degree prolapse and no palpable uterus. A small prolapsing remnant of a uterus didelphys with 2 noncanalized uterine horns was excised by laparotomy. Ultrastructural examination of subepithelial cervical connective tissue revealed collagen of normal structure, but of low concentration. The etiologies of both the Mullerian ducts anomalies and the genital prolapse are probably multifactorial. Low collagen concentration indicates a constitutional tissue weakness contributing to the development of genital prolapse. Copyright 2008 S. Karger AG, Basel.

  18. Toxocara cati (Nematoda: Ascarididae) in Didelphis albiventris (Marsupialia: Didelphidae) from Brazil: a case of pseudoparasitism.

    PubMed

    Pinto, Hudson Alves; Mati, Vitor Luís Tenório; Melo, Alan Lane de

    2014-01-01

    Eggs of Toxocara cati were found in the feces of Didelphis albiventris from a peridomestic urban environment in Brazil. Negative fecal tests following short-term captivity of the opossums, as well as the absence of ascaridids during necropsy, suggest the occurrence of pseudoparasitism. Implications of the findings for the epidemiology of toxocariasis are discussed.

  19. Experimental infection of Didelphis marsupialis with Vesicular Stomatitis New Jersey Virus

    USDA-ARS?s Scientific Manuscript database

    Although vesicular stomatitis has been present for many years in the Americas, many aspects of its natural history remain undefined. In this study we challenged five adult Virginia opossums (Didelphis marsupialis) with vesicular stomatitis New Jersey serotype virus (VSNJV). Opossums had no detecta...

  20. West Nile Virus Isolated from a Virginia Opossum (Didelphis virginiana) in Northwestern Missouri, USA, 2012

    PubMed Central

    Bosco-Lauth, Angela; Harmon, Jessica R.; Lash, R. Ryan; Weiss, Sonja; Langevin, Stanley; Savage, Harry M.; Godsey, Marvin S.; Burkhalter, Kristen; Root, J. Jeffrey; Gidlewski, Thomas; Nicholson, William L.; Brault, Aaron C.; Komar, Nicholas

    2016-01-01

    We describe the isolation of West Nile virus (WNV; Flaviviridae, Flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology. PMID:25098303

  1. West Nile virus isolated from Virginia opossum (Didelphis virginiana) in Northwest Missouri 2012

    DOE PAGES

    Bosco-Lauth, Angela; Harmon, Jessica; Lash, R. Ryan; ...

    2014-12-01

    We describe the isolation of West Nile virus (WNV; Flaviviridae, flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Furthermore, sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology.

  2. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO.

    PubMed

    Peniche-Lara, Gaspar; Ruiz-Piña, Hugo A; Reyes-Novelo, Enrique; Dzul-Rosado, Karla; Zavala-Castro, Jorge

    2016-01-01

    Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltA and 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households.

  3. Independent uterine contractions in simultaneous twin pregnancy in each horn of the uterus didelphys.

    PubMed

    Maki, Yohei; Furukawa, Seishi; Sameshima, Hiroshi; Ikenoue, Tsuyomu

    2014-03-01

    The mechanism of synchronizing uterine contractions is not fully understood. We present a case of twin pregnancy in a uterus didelphys and objectively analyze the synchrony of bilateral uterine contractions. A 32-year-old woman, with a history of vaginal septal resection during her previous vaginal delivery, became pregnant with twins in a uterus didelphys in which each uterine horn had one fetus. At 37 weeks and 6 days, the first baby was delivered vaginally. The second baby was delivered by cesarean section due to recurrent late decelerations. Operative findings confirmed the didelphys uterus. We retrospectively reviewed the timing of contractions of both uteruses. The timing was determined by visual analysis as synchronous if both uteruses contracted within 5 s. Otherwise, contractions were considered solitary. Both uterine horns contracted independently in 90% of the incidence throughout labor and delivery. From this rare case of an 'experiment by nature', we speculated that the myometrium must be histologically connected in order to synchronize uterine contractions.

  4. Natural infection of Didelphis aurita (Mammalia: Marsupialia) with Leishmania infantum in Brazil

    PubMed Central

    2012-01-01

    Background The opossum Didelphis have been considered as natural hosts of Leishmania parasites in the New World, suggesting an important role in the epidemiology of Visceral Leishmaniasis (VL). Among six extant species that belong to the genus Didelphis, only two (D. marsupialis and D. albiventris), have been mentioned as natural hosts of Leishmania infantum in Brazil and Colombia. In the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes) in tissues of Didelphis aurita naturally infected with Leishmania infantum in Brazil. We also discuss some aspects associated to the relationship between L. infantum and the geographical distribution of some species of the genus Didelphis. Methods The opossums studied were caught by wire traps (Tomahawk) in Barra de Guaratiba, a peri-urban area in Rio de Janeiro. The opossums were killed with an overdose of Thiopental sodium.At necropsy, macroscopic alterations were examined and samples from liver, spleen, lymph nodes, ear, abdominal skin, scent glands and bone marrow were collected for parasitological and molecular diagnoses. Results Forty-eight opossums were captured in an AVL endemic region, 30 being caught in a mangrove area and eighteen animals in a forest area near to some residential-yards. Among the thirty opossums trapped in the mangrove area, all of them were negative by both imprint and sera samples assayed on Dipstick Tests, that is a test based on a combination of protein-A colloidal gold conjugate and rk39 Leishmania antigen to detect anti-Leishmania antibody in serum or plasma. At the macroscopic examination one out of eighteen opossums, caught close to the forest, presented alterations compatible with spleen hypertrophy and three were positive by Dipstick Tests (16.6%) and presented amastigotes in the spleen and in one of them, the parasites were also observed in a submandibular lymph node. Leishmania infantum infections were confirmed through dot blot

  5. Natural infection of Didelphis aurita (Mammalia: Marsupialia) with Leishmania infantum in Brazil.

    PubMed

    Carreira, João Carlos Araujo; da Silva, Alba Valéria Machado; de Pita Pereira, Daniela; Brazil, Reginaldo Peçanha

    2012-06-07

    The opossum Didelphis have been considered as natural hosts of Leishmania parasites in the New World, suggesting an important role in the epidemiology of Visceral Leishmaniasis (VL). Among six extant species that belong to the genus Didelphis, only two (D. marsupialis and D. albiventris), have been mentioned as natural hosts of Leishmania infantum in Brazil and Colombia. In the present paper, it is reported for the first time, the observation of intracellular parasites (amastigotes) in tissues of Didelphis aurita naturally infected with Leishmania infantum in Brazil. We also discuss some aspects associated to the relationship between L. infantum and the geographical distribution of some species of the genus Didelphis. The opossums studied were caught by wire traps (Tomahawk) in Barra de Guaratiba, a peri-urban area in Rio de Janeiro. The opossums were killed with an overdose of Thiopental sodium.At necropsy, macroscopic alterations were examined and samples from liver, spleen, lymph nodes, ear, abdominal skin, scent glands and bone marrow were collected for parasitological and molecular diagnoses. Forty-eight opossums were captured in an AVL endemic region, 30 being caught in a mangrove area and eighteen animals in a forest area near to some residential-yards. Among the thirty opossums trapped in the mangrove area, all of them were negative by both imprint and sera samples assayed on Dipstick Tests, that is a test based on a combination of protein-A colloidal gold conjugate and rk39 Leishmania antigen to detect anti-Leishmania antibody in serum or plasma. At the macroscopic examination one out of eighteen opossums, caught close to the forest, presented alterations compatible with spleen hypertrophy and three were positive by Dipstick Tests (16.6%) and presented amastigotes in the spleen and in one of them, the parasites were also observed in a submandibular lymph node. Leishmania infantum infections were confirmed through dot blot hybridization using a L. infantum

  6. Discovery of an endemic area of Gnathostoma turgidum infection among opossums, Didelphis virginiana, in Mexico.

    PubMed

    Díaz-Camacho, Sylvia Páz; Willms, Kaethe; Rendón-Maldonado, José Guadalupe; de la Cruz-Otero, María del Carmen; Delgado-Vargas, Francisco; Robert, Lilia; Antuna, Silvia; León-Règagnon, Virginia; Nawa, Yukifumi

    2009-06-01

    Gnathostomosis, caused by Gnathostoma binucleatum, is a serious public health issue in Mexico. Although 2 other Gnathostoma spp., G. turgidum and G. lamothei, have been found in wild animals, their natural life cycle or their relation to human disease remains unclear. While we were conducting an epidemiological survey on Gnathostoma spp. in Sinaloa State, Mexico, we found an endemic area for G. turgidum in common opossums, Didelphis virginiana, located in Tecualilla, Sinaloa. The species identification was carried out by morphological and molecular biological methods. This is the first record of an endemic area for G. turgidum infection in opossums, D. virginiana, in the Americas.

  7. Congenital pouch colon in a girl associated with bilateral atresia of cervix uteri and uterus didelphys.

    PubMed

    Chadha, Rajiv; Puri, Manju; Saxena, Rahul; Agarwala, Surendrakumar; Puri, Archana; Choudhury, Subhasis Roy

    2013-04-01

    This report describes a girl with congenital pouch colon (CPC), uterus didelphys with septate vagina, and a cloacal anomaly. The girl underwent cloacal reconstruction at the age of 15 months. Subsequently, at puberty, the child had primary amenorrhea with severe cyclic abdominal pain due to endometriosis of both the uteruses and adnexal cysts with hematometra and hematosalpinx. Laparotomy with removal of both uteri and the left fallopian tube was performed. Both uteri had atresia of the cervix uteri. This report emphasizes the need for comprehensive evaluation and a long-term management strategy for associated gynecologic anomalies in girls with CPC, especially with regard to patency of the outflow tract.

  8. Blindness - resources

    MedlinePlus

    Resources - blindness ... The following organizations are good resources for information on blindness : American Foundation for the Blind -- www.afb.org Foundation Fighting Blindness -- www.blindness.org National Eye Institute -- ...

  9. INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO

    PubMed Central

    PENICHE-LARA, Gaspar; RUIZ-PIÑA, Hugo A.; REYES-NOVELO, Enrique; DZUL-ROSADO, Karla; ZAVALA-CASTRO, Jorge

    2016-01-01

    Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltAand 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households. PMID:27074326

  10. West Nile virus isolated from Virginia opossum (Didelphis virginiana) in Northwest Missouri 2012

    SciTech Connect

    Bosco-Lauth, Angela; Harmon, Jessica; Lash, R. Ryan; Weiss, Sonja; Langevin, Stanley; Savage, Harry; Marvin S. Godsey, Jr.; Burkhalter, Kristen; Root, J. Jeffrey; Gidlewski, Thomas; Nicholson, William; Brault, Aaron C.; Komar, Nicholas

    2014-12-01

    We describe the isolation of West Nile virus (WNV; Flaviviridae, flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Furthermore, sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology.

  11. Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozonn cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossum, Didelphis virginiana, from Southern Louisian

    USDA-ARS?s Scientific Manuscript database

    We examined the prevalence of antibodies to zoonotic protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoan’s of veterinary importance (Neospora caninum, Sarcocystis neurona and Besnoitia darlingi) in a population of North American opossums (Didelphis...

  12. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico

    PubMed Central

    Torres-Castro, M.; Noh-Pech, H.; Puerto-Hernández, R.; Reyes-Hernández, B.; Panti-May, A.; Hernández-Betancourt, S.; Yeh-Gorocica, A.; González-Herrera, L.; Zavala-Castro, J.; Puerto, F.I.

    2016-01-01

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico. PMID:27200271

  13. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico.

    PubMed

    Torres-Castro, M; Noh-Pech, H; Puerto-Hernández, R; Reyes-Hernández, B; Panti-May, A; Hernández-Betancourt, S; Yeh-Gorocica, A; González-Herrera, L; Zavala-Castro, J; Puerto, F I

    2016-01-01

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

  14. Mammary glands in male marsupials: I. Primordia in neonatal opossums Didelphis virginiana and Monodelphis domestica.

    PubMed

    Renfree, M B; Robinson, E S; Short, R V; Vandeberg, J L

    1990-10-01

    Neonates of the American didelphid marsupials Didelphis virginiana and Monodelphis domestica were sexed by karyotype and histologically examined on the day of birth. Mammary anlagen were found in both sexes of both species, but the neonatal males had less than one-third of the full female complement of mammary glands. Male neonates of both species also had paired scrotal bulges anterior to the genital tubercle but these were never present in females, once again raising the question of whether the pouch and scrotum are homologous structures. Mammary anlagen are not found in male neonates of the Australian marsupial species so far studied, which suggests a dichotomy in the control of some aspects of sexual differentiation in the two marsupial lineages.

  15. Normal conjunctival flora in the North American opossum (Didelphis virginiana) and raccoon (Procyon lotor).

    PubMed

    Pinard, Chantale L; Brightman, Alan H; Yeary, Teresa J; Everson, Troy D; Cox, Linda K; Chengappa, M M; Davidson, Harriet J

    2002-10-01

    We documented the normal conjunctival bacterial flora from 17 opossums (Didelphis virginiana) and 10 raccoons (Procyon lotor) trapped in Manhattan, Kansas (USA) from November 1999 to January 2000. Both raccoons and opossums were free of apparent ocular disease. The inferior conjunctival sacs of each animal were swabbed for aerobic bacterial and Mycoplasma culture and polymerase chain reaction (PCR) for Mycoplasma and Chlamydia detection. All conjunctival samples were positive for one or more species of aerobic bacteria. The most common isolate from opossums was Staphylococcus spp. Other isolates included Streptococcus spp., Bacillus spp., Corynebacterium spp., and Enterococcus faecalis. The most common isolates in raccoons was Bacillus spp. Other isolates included Streptococcus spp., Staphylococcus spp., non-hemolytic Escherichia coli, and Enterococcus faecalis. Mycoplasma culture was negative in samples from opossums and raccoons. Evidence of Mycoplasma and Chlamydia presence was detected by PCR.

  16. Spontaneous cure after natural infection with Gnathostoma turgidum (Nematoda) in Virginia opossums (Didelphis virginiana).

    PubMed

    Torres-Montoya, Hilario; Galaviz-Renteria, Xochilth; Castillo-Ureta, Hipólito; Lopez-Moreno, Hector; Nawa, Yukifumi; Bojorquez-Contreras, Angel; Sanchez-Gonzalez, Sergio; Díaz-Camacho, Sylvia; Rocha-Tirado, Rodrigo; Rendon-Maldonado, Jose

    2014-04-01

    Seasonality of the nematode Gnathostoma turgidum in Virginia opossums (Didelphis virginiana) in the wild has been reported; however, the mechanisms involved in deworming are unknown. We monitored the parasitologic and biologic changes in four Virginia opossums naturally infected with G. turgidum by coproparasitologic examination and abdominal ultrasonography. Eggs became detectable in the feces of opossums in May, peaked in July and August, and suddenly decreased in October. Adults of G. turgidum were expelled in the feces mainly in September. Ultrasonography of the liver showed slight damage during May. Lesions in the stomach appeared in April and persisted until September. The abnormalities of the liver and stomach were resolved in November. These data suggest that G. turgidum is likely expelled as a result of host immunologic mechanisms, although termination of a natural life span cannot be definitively excluded.

  17. Observations on besnoitiosis in Virginia opossum (Didelphis virginiana) from Michigan, USA.

    PubMed

    El Sheikha, Hany M; Hussein, Hussein S; Monib, Mohammad el-Salahy M; Mansfield, Linda S

    2007-04-01

    Besnoitia tissue cysts were found in five naturally-infected adult opossums (Didelphis virginiana) from Michigan. Details of the microscopy, histopathology, ultra-structure, and genetic features of the cysts were studied to identify their species-specific traits. The materials were differentiated phenotypically from cysts of other Besnoitia spp. by difference in size, pattern of tissue distribution, morphology of pellicle and nucleus, number of micronemes and rhoptries, amount of lipids and amylopectin, and presence of enigmatic bodies. Morphometric variations identified the tissue cysts and the pathologic changes in opossums host to be due to B. darlingi. The data were proved by phylogenetic analysis based on DNA sequences of the first internal transcribed spacer of nuclear rDNA. Cluster analysis showed that B. darlingi was distinct from all other Besnoitia spp. as two distinct phylogenetic clades: I- included Besnoitia spp. described from opossum (B. darlingi), sheep (B. jellisoni), rodent (B. akadoni) and rabbit (B. oryctofelisi) and clade II- encompassed parasites described from cattle (B. besnoiti), equids (B. bennetti) and reindeer (B. tarandi). The genetic attributed particular to the genus Besnoitia complemented the morphologica features and lead to accurate delimitation of Besnoitia species.

  18. Intrahepatic growth and maturation of Gnathostoma turgidum in the natural definitive opossum host, Didelphis virginiana.

    PubMed

    Díaz-Camacho, Sylvia Páz; Delgado-Vargas, Francisco; Willms, Kaethe; de la Cruz-Otero, María del Carmen; Guadalupe Rendón-Maldonado, José; Robert, Lilia; Antuna, Silvia; Nawa, Yukifumi

    2010-09-01

    Gnathostoma turgidum is a gastric nematode parasite of opossums found in the Americas. We recently found that G. turgidum juveniles appear in the liver of the opossums where they become mature adults and almost synchronously move to the stomach during certain months of the year, suggesting the importance of the liver for the growth and maturation of this species in the final hosts. In this study we attempted to detect G. turgidum larvae in the liver of opossums, Didelphis virginiana that are the natural final hosts. The results show that tiny (<3mm in length) third stage larvae (L3) appeared in the liver of opossums around November and December. Also in the liver, we found large L3 of up to about 10mm in length together with juveniles and mature adults from February to March. In spite of their length, large L3 have 4 rows of hooklets, and their gonads remained undeveloped. Morphological features of the small and large L3 of G. turgidum are described including scanning electron microscope images. The seasonal switching of the several growth stages of G. turgidum from small L3 to adult worms in the liver and eventual migration to the stomach in opossums suggests the unique feature of G. turgidum utilizing the liver as the maturation site.

  19. Prevalence and risk factors associated with Sarcocystis neurona infections in opossums (Didelphis virginiana) from central California.

    PubMed

    Rejmanek, Daniel; Vanwormer, Elizabeth; Miller, Melissa A; Mazet, Jonna A K; Nichelason, Amy E; Melli, Ann C; Packham, Andrea E; Jessup, David A; Conrad, Patricia A

    2009-12-03

    Sarcocystis neurona, a protozoal parasite shed by opossums (Didelphis virginiana), has been shown to cause significant morbidity and mortality in horses, sea otters, and other marine mammals. Over the course of 3 years (fall 2005-summer 2008), opossums from central California were tested for infection with S. neurona. Of 288 opossums sampled, 17 (5.9%) were infected with S. neurona based on the molecular characterization of sporocysts from intestinal scrapings or feces. Risk factors evaluated for association with S. neurona infection in opossums included: age, sex, location, season, presence of pouch young in females, concomitant infection, and sampling method (live-trapped or traffic-killed). Multivariate logistic regression analysis identified that opossums in the Central Valley were 9 times more likely to be infected than those near the coast (p=0.009). Similarly, opossum infection was 5 times more likely to be detected during the reproductive season (March-July; p=0.013). This first investigation of S. neurona infection prevalence and associated risk factors in opossums in the western United States can be used to develop management strategies aimed at reducing the incidence of S. neurona infections in susceptible hosts, including horses and threatened California sea otters (Enhydra lutris neries).

  20. Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California.

    PubMed

    Rejmanek, Daniel; Miller, Melissa A; Grigg, Michael E; Crosbie, Paul R; Conrad, Patricia A

    2010-05-28

    Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums.

  1. Experimental aerosol inoculation of Mycobacterium bovis in North American opossums (Didelphis virginiana).

    PubMed

    Fitzgerald, Scott D; Zwick, Laura S; Diegel, Kelly L; Berry, Dale E; Church, Steven V; Sikarskie, James G; Kaneene, John B; Reed, Willie M

    2003-04-01

    The goal of this study was to evaluate the susceptibility of North American opossums (Didelphis virginiana) to aerosol inoculation of Mycobacterium bovis at two dose levels in order to gain information on disease pathogenesis, fecal shedding of the organism, and the potential role that opossums play in the spread of this disease in nature. Six opossums received high dose (1 x 10(7) colony forming units (cfu) by aerosol inoculation, six opossums received low dose (1 x 10(3) cfu inoculation, and six opossums were sham-inoculated with sterile water and served as controls. Lungs were the most frequently infected tissues, with nine of 12 inoculated opossums positive for M. bovis on culture. Gross lesions consisted of multifocal pneumonia and enlarged lymph nodes. Microscopically, granulomatous pneumonia and granulomatous lymphadenitis associated with acid-fast bacilli were present in eight of 12 inoculated opossums. Fecal shedding of M. bovis was uncommon at both inoculation doses. While opossums were highly susceptible to aerosol inoculation of M. bovis, they did not become emaciated or develop widely disseminated lesions. From this study, opossums may transmit tuberculosis by aerosol infection to other opossums in close contact and serve as a source of infection to carnivores that feed upon them, however, transmission of the disease to large herbivores by fecal shedding or direct contact may be less likely.

  2. New Aspidoderidae species parasite of Didelphis aurita (Mammalia: Didelphidae): a light and scanning electron microscopy approach.

    PubMed

    Chagas-Moutinho, V A; Sant'anna, V; Oliveira-Menezes, A; De Souza, W

    2014-02-01

    Nematodes of the family Aspidoderidae (Nematoda: Heterakoidea) Skrjabin and Schikobalova, 1947, are widely distributed in the Americas. The family Aspidoderidae includes the subfamilies Aspidoderinae Skrjabin and Schikobalova, 1947, and Lauroiinae Skrjabin and Schikobalova, 1951. These two subfamilies are delineated by the presence or absence of cephalic cordons at the anterior region. The nematodes in the subfamily Aspidoderinae, which includes the genus AspidoderaRailliet and Henry, 1912, are represented by nematodes with anterior cephalic cordons at the anterior end. The nematodes of the genus AspidoderaRailliet and Henry, 1912, are found in the cecum and large intestine of mammals of the orders Edentata, Marsupialia and Rodentia. Species within this genus have many morphological similarities. The use of scanning electron microscopy allows the specific characterization of the species within this genus. In the present work, we describe a new species of Aspidodera parasite of the large intestine of Didelphis aurita (Mammalia: Didelphidae) Wied-Neuwied, 1826, collected from Cachoeiras de Macacu, Rio de Janeiro. The combination of light and scanning electron microscopy allowed us a detailed analysis of this nematode.

  3. CUTANEOUS EPITHELIOTROPIC T-CELL LYMPHOMA WITH METASTASES IN A VIRGINIA OPOSSUM (DIDELPHIS VIRGINIANA).

    PubMed

    Higbie, Christine T; Carpenter, James W; Choudhary, Shambhunath; DeBey, Brad; Bagladi-Swanson, Mary; Eshar, David

    2015-06-01

    A 2-yr-old, captive, intact female Virginia opossum ( Didelphis virginiana ) with a 7-mo history of ulcerative dermatitis and weight loss was euthanatized for progressive worsening of clinical signs. Initially the opossum was treated with several courses of antibiotics, both topically and systemically; systemic nonsteroidal anti-inflammatory medication; and, later, systemic glucocorticoids, with no improvement in clinical signs. Histopathologic samples of skin lesions taken 3 mo into the course of disease revealed no evidence of neoplasia; however, cytologic samples of a skin lesion taken 5 mo into the course of disease revealed mature lymphocytes, and were suggestive of cutaneous lymphoma. Postmortem histopathology revealed neoplastic cells consistent with lymphoma; these were found in the haired skin of the forearm, axilla, hind limb, face, and lateral body wall, as well as the liver, kidney, axillary lymph node, heart, and spleen. Multifocal neutrophilic and eosinophilic ulcerative and necrotizing dermatitis and folliculitis of the haired skin were also present. To the authors' knowledge, this is the first documented case of cutaneous lymphoma in a Virginia opossum and the first documented case with visceral metastases in a marsupial.

  4. Leptospira borgpetersenii from free-living white-eared opossum (Didelphis albiventris): first isolation in Brazil.

    PubMed

    Jorge, Sérgio; Hartleben, Cláudia P; Seixas, Fabiana K; Coimbra, Marco A A; Stark, Cledir B; Larrondo, Adriana G; Amaral, Marta G; Albano, Ana Paula N; Minello, Luiz F; Dellagostin, Odir A; Brod, Claudiomar S

    2012-11-01

    Leptospirosis is a zoonotic disease that occurs all over the world, caused by bacteria of the genus Leptospira. Marsupial and didelphidae families are considered susceptible to infection caused by a wide range of Leptospira serovars for which they serve as reservoirs. Thirty-three free-living white-eared opossums (Didelphis albiventris) were captured in Southern Brazil and bodily fluids were collected. From the urine samples it was possible to obtain an isolate identified as Leptospira borgpetersenii by rpoB gene sequencing and belonging to serovar Castellonis by Multilocus Variable-Number Tandem-Repeat Analysis. This is the first report of the isolation of Leptospira spp. from the white-eared opossum in Brazil. In addition, the new strain was also virulent in the hamster model of lethal leptospirosis. The microscopic agglutination test (MAT) was used for detecting the presence of antibodies against Leptospira spp. in white-eared opossum, human, cattle and canine sera using a panel of 59 Leptospira strains that included the new isolate. The inclusion of the new strain in the MAT battery increased the MAT sensitivity for canine sera. These findings suggest that the white-eared opossum is an important reservoir of pathogenic Leptospira spp. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Molecular characterization of Sarcocystis neurona strains from opossums (Didelphis virginiana) and intermediate hosts from Central California

    PubMed Central

    Rejmanek, Daniel; Miller, Melissa A.; Grigg, Michael E.; Crosbie, Paul R.; Conrad, Patricia A.

    2016-01-01

    Sarcocystis neurona is a significant cause of neurological disease in horses and other animals, including the threatened Southern sea otter (Enhydra lutris nereis). Opossums (Didelphis virginiana), the only known definitive hosts for S. neurona in North America, are an introduced species in California. S. neurona DNA isolated from sporocysts and/or infected tissues of 10 opossums, 6 horses, 1 cat, 23 Southern sea otters, and 1 harbor porpoise (Phocoena phocoena) with natural infections was analyzed based on 15 genetic markers, including the first internal transcribed spacer (ITS-1) region; the 25/396 marker; S. neurona surface antigen genes (snSAGs) 2, 3, and 4; and 10 different microsatellites. Based on phylogenetic analysis, most of the S. neurona strains segregated into three genetically distinct groups. Additionally, fifteen S. neurona samples from opossums and several intermediate hosts, including sea otters and horses, were found to be genetically identical across all 15 genetic markers, indicating that fatal encephalitis in Southern sea otters and equine protozoal myeloencephalitis (EPM) in horses is strongly linked to S. neurona sporocysts shed by opossums. PMID:20226596

  6. Postmortem scavenging by the Virginia opossum (Didelphis virginiana): Impact on taphonomic assemblages and progression.

    PubMed

    King, Kama A; Lord, Wayne D; Ketchum, Heather R; O'Brien, R Christopher

    2016-09-01

    The Virginia opossum (Didelphis virginiana) is a highly active scavenger whose behavior has significant impacts on rates of decomposition and skeletonization, which have previously not been addressed. In this study, scavenging by the opossum led to the skeletonization of carcasses in half of the accumulated degree days (ADD) of a comparable non-scavenged control carcass. Opossums used body orifices, as well as natural tears caused by the decomposition process, to access internal tissues and consume them. This activity resulted in little movement of the carcass and the retained appearance of natural undisturbed decomposition. This concealed activity has the potential to cause drastically incorrect estimates of time since deposition and post-mortem interval. Scavenging by opossums was also found to leave distinct tooth mark and other defects on bone, which have not been previously distinguished in the literature. This research suggests, beyond effects on PMI, that scavenging by opossums has been historically overlooked and misattributed to canid scavengers. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. FGF2, FGF3 and FGF4 expression pattern during molars odontogenesis in Didelphis albiventris.

    PubMed

    Dos Santos, Íria Gabriela Dias; Jorge, Erika Cristina; Copola, Aline Gonçalves Lio; Bertassoli, Bruno Machado; Goes, Alfredo Miranda de; Silva, Gerluza Aparecida Borges

    2017-03-01

    Odontogenesis is guided by a complex signaling cascade in which several molecules, including FGF2-4, ensure all dental groups development and specificity. Most of the data on odontogenesis derives from rodents, which does not have all dental groups. Didelphis albiventris is an opossum with the closest dentition to humans, and the main odontogenesis stages occur when the newborns are in the pouch. In this study, D. albiventris postnatals were used to characterize the main stages of their molars development; and also to establish FGF2, FGF3 and FGF4 expression pattern. D. albiventris postnatals were processed for histological and indirect immunoperoxidase analysis of the tooth germs. Our results revealed similar dental structures between D. albiventris and mice. However, FGF2, FGF3 and FGF4 expression patterns were observed in a larger number of dental structures, suggesting broader functions for these molecules in this opossum species. The knowledge of the signaling that determinates odontogenesis in an animal model with complete dentition may contribute to the development of therapies for the replacement of lost teeth in humans. This study may also contribute to the implementation of D. albiventris as model for Developmental Biology studies. Copyright © 2016 Elsevier GmbH. All rights reserved.

  8. Experimental infection of Didelphis marsupialis with vesicular stomatitis New Jersey virus.

    PubMed

    Trujillo, Carlos M; Rodriguez, Luis; Rodas, Juan D; Arboleda, John Jairo

    2010-01-01

    Although vesicular stomatitis has been present for many years in the Americas, many aspects of its natural history remain undefined. In this study, we challenged five adult Virginia opossums (Didelphis marsupialis) with vesicular stomatitis New Jersey serotype virus (VSNJV). Opossums had no detectable antibodies against VSNJV prior to being inoculated with 10(6.5) median tissue culture infective doses (TCID(50)) of VSNJV by two routes; intraepithelial/subepithelial (IE/SE) inoculation and scarification in the muzzle (SM). Clinical response was monitored daily and animals were tested for viral shedding. All infected animals developed vesicles and ulcers on the tongue and inflammation of the nasal alar folds. Virus was isolated from esophagus-pharynx, nasal, and from ocular swabs and lesions samples. The failure to detect viremia in these animals indicates that a source other than blood may be required for transmission to insect vectors. Our results suggest that D. marsupialis could play a role in the maintenance of VSNJV outside of domestic animal populations and could provide a model to study vesicular stomatitis virus pathogenesis.

  9. Cone pigments in a North American marsupial, the opossum (Didelphis virginiana).

    PubMed

    Jacobs, Gerald H; Williams, Gary A

    2010-05-01

    Only two of the four cone opsin gene families found in vertebrates are represented in contemporary eutherian and marsupial species. Recent genetic studies of two species of South American marsupial detected the presence of representatives from two of the classes of cone opsin genes and the structures of these genes predicted cone pigments with respective peaks in the ultraviolet and long-wavelength portions of the spectrum. The Virginia opossum (Didelphis virginiana), a profoundly nocturnal animal, is the only marsupial species found in North America. The prospects for cone-based vision in this species were examined through recordings of the electroretinogram (ERG), a commonly examined retinal response to photic stimulation. Recorded under flickering-light conditions that elicit signals from cone photoreceptors, the spectral sensitivity of the opossum eye is well accounted for by contributions from the presence of a single cone pigment having peak absorption at 561-562 nm. A series of additional experiments that employed various chromatic adaptation paradigms were conducted in a search for possible contributions from a second (short-wavelength sensitive) cone pigment. We found no evidence that such a mechanism contributes to the ERG in this marsupial.

  10. Coccidial dispersion across New World marsupials: Klossiella tejerai Scorza, Torrealba & Dagert, 1957 (Apicomplexa: Adeleorina) from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) (Mammalia: Didelphimorphia).

    PubMed

    Dos Santos, Caroline Spitz; Berto, Bruno Pereira; do Bomfim Lopes, Bruno; Cordeiro, Matheus Dias; da Fonseca, Adivaldo Henrique; Filho, Walter Leira Teixeira; Lopes, Carlos Wilson Gomes

    2014-09-01

    Klossiella tejerai Scorza, Torrealba & Dagert, 1957 is a primitive coccidian parasite reported from the New World marsupials Didelphis marsupialis (Linnaeus) and Marmosa demerarae (Thomas). The current work describes K. tejerai from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) in Southeastern Brazil, evidencing the coccidial dispersion across opossums of the same family. The sporocysts recovered from urine samples were ellipsoidal, 20.4 × 12.7 µm, with sporocyst residuum composed of scattered spherules and c.13 sporozoites per sporocyst, with refractile bodies and nucleus. Macrogametes, microgametes, sporonts, sporoblasts/sporocysts were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. Didelphis marsupialis should not have transmitted K. tejerai to D. aurita because they are not sympatric; however M. demerarae is sympatric with D. marsupialis and D. aurita. Therefore, D. aurita becomes the third host species for K. tejerai in South America.

  11. Occurrence of gastrointestinal protozoa in Didelphis albiventris (opossum) in the central region of Rio Grande do Sul state.

    PubMed

    Zanette, Régis A; da Silva, Aleksandro S; Lunardi, Fabiane; Santurio, Janio M; Monteiro, Silvia G

    2008-06-01

    The aim of this study was to evaluate the parasitism by gastrointestinal protozoa in Didelphis albiventris (opossum) in the central region of Rio Grande do Sul state. Fecal samples from six free living opossums were collected for research of parasites. Samples were analyzed by the centrifugal-flotation method with zinc sulfate and parasites were identified microscopically based on (oo)cyst size and morphology. Cysts of Giardia sp. and oocysts of Cryptosporidium sp. and Eimeria sp. were observed in four of the six opossums. All four infected marsupials showed mild infection by protozoa. This is the first report of Giardia sp. in D. albiventris.

  12. Color blindness

    MedlinePlus

    ... have trouble telling the difference between red and green. This is the most common type of color ... color blindness often have problems seeing reds and greens, too. The most severe form of color blindness ...

  13. Prevalence of Sarcocystis species sporocysts in Northern Virginia opossums (Didelphis virginiana).

    PubMed

    Elsheikha, Hany M; Murphy, Alice J; Mansfield, Linda S

    2004-08-01

    A total of 206 Virginia opossums ( Didelphis virginiana) collected from the mid-Michigan region, United States, during a period extending from 1996 to 2002 were sampled for the presence of Sarcocystis spp sporocysts. All isolates were phenotypically identified as Sarcocystis spp and genotyped to the species level by PCR-based techniques. The overall prevalence of Sarcocystis spp in opossums was 18% (37/206). The prevalence of Sarcocystis spp differed significantly with age ( P<0.001) and adult opossums were more commonly infected (14.6%; 30/206) than juveniles (3.4%; 7/206). No significant difference in the prevalence of Sarcocystis spp infection was observed between male and female ( P<0.15). The highest prevalence was recorded during summer (9.2%; 19/206). PCR-RFLP analyses demonstrated the majority of Sarcocystis isolates to be S. neurona, with some animals co-infected with sporocysts of S. falcatula. Out of the 37 Sarcocystis-infected opossums, 23 (62%) had sporocysts of S. neurona only, four (11%) had sporocysts of S. falcatula only, and eight (22%) had a mixture of S. neurona and S. falcatula sporocysts. These findings indicate that mixed Sarcocystis infections in opossums are common. The propensity for Sarcocystis spp to co-exist in the opossum gut enhances dissemination and environmental contamination with these coccidia. Additionally, this increases the chance for sexual recombination between Sarcocystis spp, given the proclivity of these species to reproduce sexually at high numbers in the intestinal cells of their definitive host.

  14. The transcriptome of the Didelphis virginiana opossum kidney OK proximal tubule cell line.

    PubMed

    Eshbach, Megan L; Sethi, Rahil; Avula, Raghunandan; Lamb, Janette; Hollingshead, Deborah J; Finegold, David N; Locker, Joseph D; Chandran, Uma R; Weisz, Ora A

    2017-09-01

    The OK cell line derived from the kidney of a female opossum Didelphis virginiana has proven to be a useful model in which to investigate the unique regulation of ion transport and membrane trafficking mechanisms in the proximal tubule (PT). Sequence data and comparison of the transcriptome of this cell line to eutherian mammal PTs would further broaden the utility of this culture model. However, the genomic sequence for D. virginiana is not available and although a draft genome sequence for the opossum Monodelphis domestica (sequenced in 2012 by the Broad Institute) exists, transcripts sequenced from both species show significant divergence. The M. domestica sequence is not highly annotated, and the majority of transcripts are predicted rather than experimentally validated. Using deep RNA sequencing of the D. virginiana OK cell line, we characterized its transcriptome via de novo transcriptome assembly and alignment to the M. domestica genome. The quality of the de novo assembled transcriptome was assessed by the extent of homology to sequences in nucleotide and protein databases. Gene expression levels in the OK cell line, from both the de novo transcriptome and genes aligned to the M. domestica genome, were compared with publicly available rat kidney nephron segment expression data. Our studies demonstrate the expression in OK cells of numerous PT-specific ion transporters and other key proteins relevant for rodent and human PT function. Additionally, the sequence and expression data reported here provide an important resource for genetic manipulation and other studies on PT cell function using these cells. Copyright © 2017 the American Physiological Society.

  15. PULMONARY LESIONS CAUSED BY THE LUNGWORM (DIDELPHOSTRONGYLUS HAYESI) IN THE OPOSSUM (DIDELPHIS VIRGINIANA) IN COLIMA, MEXICO.

    PubMed

    López-Crespo, Rubén A; López-Mayagoitia, Alfonso; Ramírez-Romero, Rafael; Martínez-Burnes, Julio; Prado-Rebolledo, Omar F; García-Márquez, Luis J

    2017-06-01

    Didelphostrongylus hayesi is an important and prevalent pulmonary nematode in the opossum ( Didelphis virginiana ). An in-depth description of the pulmonary lesions caused by this nematode is lacking. The objective of this investigation was to make a detailed account of the gross, subgross, and microscopic changes that occur in the lungs of opossums naturally infected with D. hayesi. Forty-four opossums trapped in the state of Colima, Mexico, were euthanized by an overdose of barbiturates. Following a postmortem examination, the right lung was cut from the main bronchi and placed in a Petri dish containing a saline solution for the detection and identification of live parasites. The left lung was fixed and cut serially for subgross microscopic examination and sections of lung were cut and stained for histopathologic examination. The most remarkable gross change in parasitized lungs was a poorly collapsible pulmonary parenchyma and mild emphysema. The right lung tested positive for lungworms on gross examination in 20/44, and 11/44 (25%) of the left lungs showed tan nodules on the pleural surface. Microscopically, the bronchi of 20/44 animals harbored adult and larval stages of D. hayesi (left lung), the same 20 opossums from which nematodes were grossly evident at necropsy (right lung). Adults and larvae were present in bronchi, bronchioles, and alveoli mixed with desquamated cells and many eosinophils, and to a lesser extent neutrophils, alveolar macrophages, and giant cells. Bronchi and bronchioles exhibited goblet cell hyperplasia and metaplasia respectively, and infiltration of lymphoplasmacytic cells in the interstitium and lamina propria. The tan nodules consisted of focal alveolar endogenous lipidosis, which likely resulted from parasitic airway obstruction. The lungs of 3/20 parasitized opossums also showed alveolar bronchiolization (Lambertosis). The absence of Eucoleus aerophilus or bacterial pneumonia incriminates D. hayesi as the putative cause of

  16. Blind Astronomers

    NASA Astrophysics Data System (ADS)

    Hockey, Thomas A.

    2011-01-01

    The phrase "blind astronomer” is used as an allegorical oxymoron. However, there were and are blind astronomers. What of famous blind astronomers? First, it must be stated that these astronomers were not martyrs to their craft. It is a myth that astronomers blind themselves by observing the Sun. As early as France's William of Saint-Cloud (circa 1290) astronomers knew that staring at the Sun was ill-advised and avoided it. Galileo Galilei did not invent the astronomical telescope and then proceed to blind himself with one. Galileo observed the Sun near sunrise and sunset or through projection. More than two decades later he became blind, as many septuagenarians do, unrelated to their profession. Even Isaac Newton temporarily blinded himself, staring at the reflection of the Sun when he was a twentysomething. But permanent Sun-induced blindness? No, it did not happen. For instance, it was a stroke that left Scotland's James Gregory (1638-1675) blind. (You will remember the Gregorian telescope.) However, he died days later. Thus, blindness little interfered with his occupation. English Abbot Richard of Wallingford (circa 1291 - circa 1335) wrote astronomical works and designed astronomical instruments. He was also blind in one eye. Yet as he further suffered from leprosy, his blindness seems the lesser of Richard's maladies. Perhaps the most famous professionally active, blind astronomer (or almost blind astronomer) is Dominique-Francois Arago (1786-1853), director until his death of the powerful nineteenth-century Paris Observatory. I will share other _ some poignant _ examples such as: William Campbell, whose blindness drove him to suicide; Leonhard Euler, astronomy's Beethoven, who did nearly half of his life's work while almost totally blind; and Edwin Frost, who "observed” a total solar eclipse while completely sightless.

  17. Evaluation of a rapid immunochromatographic dipstick test for detection of antibodies to Trypanosoma cruzi in dogs experimentally infected with isolates obtained from opossums (Didelphis virginiana), armadillos (Dasypus novemcinctus), and dogs (Canis familiaris) from the United States.

    PubMed

    Rosypal, Alexa C; Hill, Roderick; Lewis, Samantha; Barr, Stephen C; Valadas, Samantha; Gennari, Solange Maria; Lindsay, David S

    2011-02-01

    Dogs are reservoir hosts for Trypanosoma cruzi , the causative agent of American trypanosomiasis. A rapid immunochromatographic dipstick test (ICT) is available commercially for canine serological testing. The ICT was developed with the use of sera from South American dogs, but it is not routinely used in the United States. We evaluated the utility of the ICT in detecting anti-T. cruzi antibodies in dogs from the United States. Dogs (N  =  64) were experimentally infected with United States' isolates of T. cruzi from an opossum (Didelphis virginiana), an armadillo (Dasypus novemcinctus), and a domestic dog (Canis familiaris), and were tested after experimental infection. Sera from uninfected United States dogs (n  =  79; hemaculture negative) were used as negative controls. In a blind study, sera were tested by the ICT and compared to the indirect immunofluorescent antibody test with the use of Brazil-strain epimastigotes as antigen. The sensitivity of the ICT was 91% and the specificity was 98% in dogs experimentally infected with United States isolates. Our study indicates that the ICT could be a useful screening tool for serological surveillance of canine T. cruzi exposure in the United States.

  18. Surveillance and movements of Virginia opossum (Didelphis virginiana) in the bovine tuberculosis region of Michigan.

    PubMed

    Walter, W D; Fischer, J W; Anderson, C W; Marks, D R; Deliberto, T; Robbe-Austerman, S; Vercauteren, K C

    2013-07-01

    Wildlife reservoir hosts of bovine tuberculosis (bTB) include Eurasian badgers (Meles meles) and brushtail possum (Trichosurus vulpecula) in the UK and New Zealand, respectively. Similar species warrant further investigation in the northern lower peninsula of Michigan, USA due to the continued presence of bTB on cattle farms. Most research in Michigan, USA has focused on interactions between white-tailed deer (Odocoileus virginianus) and cattle (Bos taurus) for the transmission of the infectious agent of bTB, Mycobacterium bovis, due to high deer densities and feeding practices. However, limited data are available on medium-sized mammals such as Virginia opossum (Didelphis virginiana; hereafter referred to as opossum) and their movements and home range in Michigan near cattle farms. We conducted surveillance of medium-sized mammals on previously depopulated cattle farms for presence of M. bovis infections and equipped opossum with Global Positioning System (GPS) technology to assess potential differences in home range between farms inside and outside the bTB core area that has had cattle test positive for M. bovis. On farms inside the bTB core area, prevalence in opossum was comparable [6%, 95% confidence interval (CI) 2.0-11.0] to prevalence in raccoon (Procyon lotor; 4%, 95% CI 1.0-9.0, P=0.439) whereas only a single opossum tested positive for M. bovis on farms outside the bTB core area. The prevalence in opossum occupying farms that had cattle test positive for M. bovis was higher (6.4%) than for opossum occupying farms that never had cattle test positive for M. bovis (0.9%, P=0.01). Mean size of home range for 50% and 95% estimates were similar by sex (P=0.791) both inside or outside the bTB core area (P=0.218). Although surveillance efforts and home range were not assessed on the same farms, opossum use of farms near structures was apparent as was selection for farms over surrounding forested habitats. The use of farms, stored feed, and structures by opossum

  19. [Global blindness].

    PubMed

    Schulze Schwering, M

    2007-10-01

    Worldwide there are 37 million people who are completely blind and another 112 million whose sight is severely restricted. Of all blind people throughout the world, 85% live in developing countries. In three quarters of cases, blindness could be prevented or treated. The VISION 2020 campaign is dedicated to halving the number of people suffering from the diseases leading to blindness by means of disease control, training of specialist ophthalmic staff and development of appropriate infrastructures. More effort is needed if these goals are to be met. German ophthalmologists engaged in conservative and surgical treatments who join in and support VISION 2020 will be welcomed.

  20. Lack of Sarcocystis neurona antibody response in Virginia opossums (Didelphis virginiana) fed Sarcocystis neurona-infected muscle tissue.

    PubMed

    Cheadle, M A; Lindsay, D S; Greiner, E C

    2006-06-01

    Serum was collected from laboratory-reared Virginia opossums (Didelphis virginiana) to determine whether experimentally infected opossums shedding Sarcocystis neurona sporocysts develop serum antibodies to S. neurona merozoite antigens. Three opossums were fed muscles from nine-banded armadillos (Dasypus novemcinctus), and 5 were fed muscles from striped skunks (Mephitis mephitis). Serum was also collected from 26 automobile-killed opossums to determine whether antibodies to S. neurona were present in these opossums. Serum was analyzed using the S. neurona direct agglutination test (SAT). The SAT was modified for use with a filter paper collection system. Antibodies to S. neurona were not detected in any of the serum samples from opossums, indicating that infection in the opossum is localized in the small intestine. Antibodies to S. neurona were detected in filter-paper-processed serum samples from 2 armadillos naturally infected with S. neurona.

  1. Molecular characterization of an opossum Didelphis albiventris (Marsupialia: Didelphidae) population in an urban fragment of the Brazilian Atlantic rainforest and support to species barcode identification.

    PubMed

    Sousa, L C C; Gontijo, C M F; Lacorte, G A; Meireles, S N; Silva, A P; Fonseca, C G

    2012-08-16

    We made a molecular study of 40 opossums, Didelphis albiventris, from an urban fragment of the Atlantic Rainforest in southeastern Brazil, analyzing a 653-bp sequence of cytochrome c oxidase, subunit I. We found three close connected haplotypes, with low nucleotide diversity and a haplotype diversity of 59.1% and confirmed sympatry between D. albiventris and D. aurita in this region. The clear phylogenetic separation shows the appropriateness of DNA barcode identification methodology for effectively discriminating between these opossum species.

  2. Sarcocystis neurona and Neospora caninum in Brazilian opossums (Didelphis spp.): Molecular investigation and in vitro isolation of Sarcocystis spp.

    PubMed

    Gondim, Leane S Q; Jesus, Rogério F; Ribeiro-Andrade, Müller; Silva, Jean C R; Siqueira, Daniel B; Marvulo, Maria F V; Aléssio, Felipe M; Mauffrey, Jean-François; Julião, Fred S; Savani, Elisa San Martin Mouriz; Soares, Rodrigo M; Gondim, Luís F P

    2017-08-30

    Sarcocystis neurona and Neospora spp. are protozoan parasites that induce neurological diseases in horses and other animal species. Opossums (Didelphis albiventris and Didelphis virginiana) are definitive hosts of S. neurona, which is the major cause of equine protozoal myeloencephalitis (EPM). Neospora caninum causes abortion in cattle and infects a wide range of animal species, while N. hughesi is known to induce neurologic disease in equids. The aims of this study were to investigate S. neurona and N. caninum in tissues from opossums in the northeastern Brazil, and to isolate Brazilian strains of Sarcocystis spp. from wild opossums for comparison with previously isolated strains. Carcasses of 39 opossums from Bahia state were available for molecular identification of Sarcocystis spp. and N. caninum in their tissues, and for sporocyst detection by intestinal scraping. In addition, Sarcocystis-like sporocysts from nine additional opossums, obtained in São Paulo state, were tested. Sarcocystis DNA was found in 16 (41%) of the 39 opossums' carcasses; N. caninum DNA was detected in tissues from three opossums. The sporocysts from the nine additional opossums from São Paulo state were tested by bioassay and induced infection in nine budgerigars, but in none of the gamma-interferon knockout mice. In vitro isolation was successful using tissues from all nine budgerigars. The isolated strains were maintained in CV-1 and Vero cells. Three of nine isolates presented contamination in cell culture and were discarded. Analysis of six isolates based on five loci showed that these parasites were genetically different from each other and also distinct from S. neurona, S. falcatula, S. lindsayi, and S. speeri. In conclusion, opossums in the studied regions were infected with N. caninum and Sarcocystis spp. and represent a potential source of infection to other animals. This is the first report of N. caninum infection in tissues from black-eared opossum (D. aurita or D

  3. Acute blindness.

    PubMed

    Abboud, H; Sabbagh, C

    2008-11-01

    A 15-year-old man presenting with cortical blindness as the initial symptom of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) is reported. He showed fluctuating consciousness and severe occipital headache with nausea and vomiting. T2 and diffusion-weighted magnetic resonance imaging showed high signal intensity in the occipital lobes. Electroencephalography showed diffuse sharp waves with focal epileptic discharges over the posterior region. The nature of stroke-like episodes and seizure mechanisms is unexplained in MELAS. Consequently, the possible mechanisms of the cortical blindness in this case are discussed.

  4. Inhibition of the hemorrhagic and proteolytic activities of Lansberg's hognose pit viper (Porthidium lansbergii hutmanni) venom by opossum (Didelphis marsupialis) serum: isolation of Didelphis marsupialis 0.15Dm fraction on DEAE-cellulose chromatography.

    PubMed

    Pineda, María E; Girón, María E; Estrella, Amalid; Sánchez, Elda E; Aguilar, Irma; Fernandez, Irma; Vargas, Alba M; Scannone, Héctor; Rodríguez-Acosta, Alexis

    2008-01-01

    Earlier studies have revealed the ability of sera from several mammals to neutralize the toxic effects of snake venom. The Venezuelan opossum (Didelphis marsupialis) is one that has been found to inhibit hemorrhagic and proteolytic activities of venoms from many species of snakes. In this article it is shown that the opossum sera and its 0.15DM fraction were able to completely neutralize both hemorrhagic and hydrolysis (proteolysis) of casein effects induced by venom of the Lansberg's hognose pit viper (Porthidium lansbergii hutmanni). We have used DEAE-cellulose ion exchange chromatography to collect protein fractions from D. marsupialis sera which were able to defend mice from the lethal effects of P.l. hutmanni venom. The fractions separated were homogeneous by conventional electrophoresis using SDS-PAGE. The protein bands obtained contained molecular weights of approximately 6 to 220 kDa. These results revealed the presence of proteases inhibitors in the opossum sera fractions and the inhibition of venom activity by opossum sera suggesting a reciprocal adaptation at the molecular level.

  5. Blindness Clues

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Age-related macular degeneration is the leading cause of blindness in older adults, yet researchers are still in the dark about many of the factors that cause this incurable disease. But new insight from University of Florida (UF) and German researchers about a genetic link between rhesus monkeys with macular degeneration and humans could unlock…

  6. Blind Ambition

    ERIC Educational Resources Information Center

    Olson, Catherine Applefeld

    2009-01-01

    No matter how dedicated they may be, some teachers are daunted by extreme challenges. Carol Agler, music director at the Ohio State School for the Blind (OSSB), is not one of those teachers. Since joining the OSSB staff 11 years ago, Agler has revived the school's long-dormant band program and created its first marching band. Next January, she…

  7. Blindness Clues

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Age-related macular degeneration is the leading cause of blindness in older adults, yet researchers are still in the dark about many of the factors that cause this incurable disease. But new insight from University of Florida (UF) and German researchers about a genetic link between rhesus monkeys with macular degeneration and humans could unlock…

  8. Prevalence of agglutinating antibodies to Sarcocystis neurona in skunks (Mephitis Mephitis), raccoons (Procyon lotor), and opossums (Didelphis Virginiana) from Connecticut.

    PubMed

    Mitchell, Sheila M; Richardson, Dennis J; Cheadle, M Andy; Zajac, Anne M; Lindsay, David S

    2002-10-01

    Equine protozoal myeloencephalitis is the most important protozoan disease of horses in North America and is usually caused by Sarcocystis neurona. Natural cases of encephalitis caused by S. neurona have been reported in skunks (Mephitis mephitis) and raccoons (Procyon lotor). Opossums (Didelphis spp.) are the only known definitive host. Sera from 24 striped skunks, 12 raccoons, and 7 opossums (D. virginiana) from Connecticut were examined for agglutinating antibodies to S. neurona using the S. neurona agglutination test (SAT) employing formalin-fixed merozoites as antigen. The SAT was validated for skunk sera using pre- and postinfection serum samples from 2 experimentally infected skunks. Of the 24 (46%) skunks 11 were positive, and all 12 raccoons were positive for S. neurona antibodies. None of the 7 opossums was positive for antibodies to S. neurona. These results suggest that exposure to sporocysts of S. neurona by intermediate hosts is high in Connecticut. The absence of antibodies in opossums collected from the same areas is most likely because of the absence of systemic infection in the definitive host.

  9. Genetically different isolates of Trypanosoma cruzi elicit different infection dynamics in raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana).

    PubMed

    Roellig, Dawn M; Ellis, Angela E; Yabsley, Michael J

    2009-12-01

    Trypanosoma cruzi is a genetically and biologically diverse species. In the current study we determined T. cruzi infection dynamics in two common North American reservoirs, Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor). Based on previous molecular and culture data from naturally-exposed animals, we hypothesised that raccoons would have a longer patent period than opossums, and raccoons would be competent reservoirs for both genotypes T. cruzi I (TcI) and TcIIa, while opossums would only serve as hosts for TcI. Individuals (n=2 or 3) of each species were inoculated with 1x10(6) culture-derived T. cruzi trypomastigotes of TcIIa (North American (NA) - raccoon), TcI (NA - opossum), TcIIb (South American - human), or both TcI and TcIIa. Parasitemias in opossums gradually increased and declined rapidly, whereas parasitemias peaked sooner in raccoons and they maintained relatively high parasitemia for 5weeks. Raccoons became infected with all three T. cruzi strains, while opossums only became infected with TcI and TcIIb. Although opossums were susceptible to TcIIb, infection dynamics were dramatically different compared with TcI. Opossums inoculated with TcIIb seroconverted, but parasitemia duration was short and only detectable by PCR. In addition, raccoons seroconverted sooner (3-7days post inoculation) than opossums (10days post inoculation). These data suggest that infection dynamics of various T. cruzi strains can differ considerably in different wildlife hosts.

  10. Spontaneous neoplasms in captive Virginia opossums ( Didelphis virginiana): a retrospective case series (1989-2014) and review of the literature.

    PubMed

    Pope, Jenny P; Donnell, Robert L

    2017-05-01

    This retrospective project summarizes the types of neoplasms identified in Virginia opossums ( Didelphis virginiana) presented to the University of Tennessee, College of Veterinary Medicine (UTCVM) postmortem service in 1989-2014 and serves as a review of the literature. Of the 85 Virginia opossums identified from the UTCVM case database, there were 17 diagnoses of neoplasia from 12 cases (14%). These cases included 8 females, 2 males, and 2 neutered males. All opossums with known ages (11 of 12) were >2 y old. Pulmonary tumors, specifically minimally invasive or lepidic-predominant adenocarcinomas, were the most common diagnosis and accounted for 53% (9 of 17) of the neoplasms. Additional tumors included acute myeloid leukemia with eosinophil maturation, hepatic hemangiosarcoma, sarcoma (unknown origin), squamous cell carcinoma, disseminated mast cell tumor, trichoblastoma, thyroid adenoma, and an osteoma. These findings serve as a reference for the types of spontaneous neoplasms in Virginia opossums; based on these findings, neoplasia should be considered as a differential in mature captive Virginia opossums.

  11. Experimental Aerosol Inoculation and Investigation of Potential Lateral Transmission of Mycobacterium bovis in Virginia Opossum (Didelphis virginiana).

    PubMed

    Fenton, Karla A; Fitzgerald, Scott D; Bolin, Steve; Kaneene, John; Sikarskie, James; Greenwald, Rena; Lyashchenko, Konstantin

    2012-01-01

    An endemic focus of Mycobacterium bovis (M. bovis) infection in the state of Michigan has contributed to a regional persistence in the animal population. The objective of this study was to determine if Virginia opossums (Didelphis virginiana) contribute to disease persistence by experimentally assessing intraspecies lateral transmission. One wild caught pregnant female opossum bearing 11 joeys (young opossum) and one age-matched joey were obtained for the study. Four joeys were aerosol inoculated with M. bovis (inoculated), four joeys were noninoculated (exposed), and four joeys plus the dam were controls. Four replicate groups of one inoculated and one exposed joey were housed together for 45 days commencing 7 days after experimental inoculation. At day 84 opossums were sacrificed. All four inoculated opossums had a positive test band via rapid test, culture positive, and gross/histologic lesions consistent with caseogranulomatous pneumonia. The exposed and control groups were unremarkable on gross, histology, rapid test, and culture. In conclusion, M. bovis infection within the inoculated opossums was confirmed by gross pathology, histopathology, bacterial culture, and antibody tests. However, M. bovis was not detected in the control and exposed opossums. There was no appreciable lateral transmission of M. bovis after aerosol inoculation and 45 days of cohabitation between infected and uninfected opossums.

  12. Morphologic characterization and distribution of endocrine cells in the large intestine of the opossum Didelphis aurita (Wied-Neuwied, 1826).

    PubMed

    Dos Santos, Daiane Cristina Marques; Cupertino, Marli do Carmo; Novaes, Rômulo Dias; Soares, Ítalo Augusto da Costa; Fonseca, Cláudio César; da Matta, Sérgio Luis Pinto; Sartori, Sirlene Souza Rodrigues

    2013-10-01

    This study was designed to investigate the morphology and distribution of argyrophil, argentaffins, and insulin-immunoreactive endocrine cells in the large intestine of the opossum Didelphis aurita. Fragments of the large intestine of 10 male specimens of the opossum D. aurita were collected, processed, and submitted for histochemistry, immunohistochemistry, and scanning electron microscopy. The tunics of the large intestine of D. aurita presented morphological characteristics that have already been described for eutherian mammals. The morphometric data showed that the inner circular layer of all portions and regions analyzed is thicker relative to the longitudinal layer, and these layers in the rectum are thicker compared to the cecum and ascending colon. The majority of mucus-secreting cells have acid and neutral mucins, suggesting that the production of mucus is mixed. The number of these cells increases in the region of the cecum toward the rectum. Important findings include the occurrence of argyrophil, argentaffins, and insulin-immunoreactive endocrine cells in all segments of the large intestine of the opossum (D. aurita). To the best of our knowledge, this is the first report about the presence of insulin-immunoreactive endocrine cells in the large intestine of the opossum (D. aurita). Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Genetically different isolates of Trypanosoma cruzi elicit different infection dynamics in raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana)

    PubMed Central

    Roellig, Dawn M.; Ellis, Angela E.; Yabsley, Michael J.

    2009-01-01

    Trypanosoma cruzi is a genetically and biologically diverse species. In the current study we determined T. cruzi infection dynamics in two common North American reservoirs, Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor). Based on previous molecular and culture data from naturally-exposed animals, we hypothesized that raccoons would have a longer patent period than opossums, and raccoons would be competent reservoirs for both genotypes T. cruzi I (TcI) and TcIIa, while opossums would only serve as hosts for TcI. Individuals (n = 2 or 3) of each species were inoculated with 1 × 106 culture-derived T. cruzi trypomastigotes of TcIIa (North American (NA) - raccoon), TcI (NA - opossum), TcIIb (South American - human), or both TcI and TcIIa. Parasitemias in opossums gradually increased and declined rapidly, whereas parasitemias peaked sooner in raccoons and they maintained relatively high parasitemia for 5 weeks. Raccoons became infected with all three T. cruzi strains, while opossums only became infected with TcI and TcIIb. Although opossums were susceptible to TcIIb, infection dynamics were dramatically different compared with TcI. Opossums inoculated with TcIIb seroconverted, but parasitemia duration was short and only detectable by PCR. In addition, raccoons seroconverted sooner (3–7 days post inoculation) than opossums (10 days post inoculation). These data suggest that infection dynamics of various T. cruzi strains can differ considerably in different wildlife hosts. PMID:19607833

  14. Experimental Aerosol Inoculation and Investigation of Potential Lateral Transmission of Mycobacterium bovis in Virginia Opossum (Didelphis virginiana)

    PubMed Central

    Fenton, Karla A.; Fitzgerald, Scott D.; Bolin, Steve; Kaneene, John; Sikarskie, James; Greenwald, Rena; Lyashchenko, Konstantin

    2012-01-01

    An endemic focus of Mycobacterium bovis (M. bovis) infection in the state of Michigan has contributed to a regional persistence in the animal population. The objective of this study was to determine if Virginia opossums (Didelphis virginiana) contribute to disease persistence by experimentally assessing intraspecies lateral transmission. One wild caught pregnant female opossum bearing 11 joeys (young opossum) and one age-matched joey were obtained for the study. Four joeys were aerosol inoculated with M. bovis (inoculated), four joeys were noninoculated (exposed), and four joeys plus the dam were controls. Four replicate groups of one inoculated and one exposed joey were housed together for 45 days commencing 7 days after experimental inoculation. At day 84 opossums were sacrificed. All four inoculated opossums had a positive test band via rapid test, culture positive, and gross/histologic lesions consistent with caseogranulomatous pneumonia. The exposed and control groups were unremarkable on gross, histology, rapid test, and culture. In conclusion, M. bovis infection within the inoculated opossums was confirmed by gross pathology, histopathology, bacterial culture, and antibody tests. However, M. bovis was not detected in the control and exposed opossums. There was no appreciable lateral transmission of M. bovis after aerosol inoculation and 45 days of cohabitation between infected and uninfected opossums. PMID:22701815

  15. Endogenous Life Cycle of Eimeria marmosopos (Apicomplexa: Eimeriidae) from the Opossum, Didelphis marsupialis (Didelphimorphia: Didelphidae) in Costa Rica.

    PubMed

    Chinchilla, Misael; Valerio, Idalia; Duszynski, Donald

    2015-08-01

    The endogenous life cycle of Eimeria marmosopos was studied in experimentally infected young opossums, Didelphis marsupialis . All the endogenous stages were located in the epithelial cells of villi in the small intestine. Giemsa-stained mucosal scrapings and histological sections were studied for the diagnosis of all the life cycle stages. Eimeria marmosopos has 3 generations of meronts (M) that differ by size, shape, and number of merozoites (m), which also differ in their size, shape, and location of their nuclei within the cytoplasm of the meronts. The 3 meront types, M(1)-M(3), respectively, had 8-15 (m(1)), 4-9 (m(2)), and 22-30 (m(3)) merozoites. Macrogametocytes and microgametocytes, as well as macrogametes and microgametes, completed the sexual cycle, finishing with the formation of unsporulated oocysts. This parasite's endogenous development produced severe intestinal lesions in experimentally infected opossums. There are 56 Eimeria species known from all marsupials worldwide, but this is the first complete life cycle in which both the asexual and sexual stages have been documented.

  16. Foundation Fighting Blindness

    MedlinePlus

    ... Campaign to End Blindness Other Ways to Fight Blindness Corporate Support Volunteer Take Action Honor a Loved ... taking place nationwide. Join Us We Are Ending Blindness The urgent mission of the Foundation Fighting Blindness ...

  17. Acute Blindness.

    PubMed

    Meekins, Jessica M

    2015-09-01

    Sudden loss of vision is an ophthalmic emergency with numerous possible causes. Abnormalities may occur at any point within the complex vision pathway, from retina to optic nerve to the visual center in the occipital lobe. This article reviews specific prechiasm (retina and optic nerve) and cerebral cortical diseases that lead to acute blindness. Information regarding specific etiologies, pathophysiology, diagnosis, treatment, and prognosis for vision is discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Congenitally Blind Counselor, Adventitiously Blind Client.

    ERIC Educational Resources Information Center

    Roberts, A. H.

    1994-01-01

    A counselor blind from birth describes personal difficulties in fully understanding the experience of clients who are adventitiously blind. Congenitally blind counselors are urged to recognize that adaptive methods cannot compensate for the panoramic view of the environment provided by vision and that recently blinded individuals need to deal with…

  19. Anomalous colour in Neotropical mammals: a review with new records for Didelphis sp. (Didelphidae, Didelphimorphia) and Arctocephalus australis (Otariidae, Carnivora).

    PubMed

    Abreu, M S L; Machado, R; Barbieri, F; Freitas, N S; Oliveira, L R

    2013-02-01

    Anomalous colourations occur in many tropical vertebrates. However, they are considered rare in wild populations, with very few records for the majority of animal taxa. We report two new cases of anomalous colouration in mammals. Additionally, we compiled all published cases about anomalous pigmentation registered in Neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. Every record was classified as albinism, leucism, piebaldism or eventually as undetermined pigmentation. As results, we report the new record of a leucistic specimen of opossum (Didelphis sp.) in southern Brazil, as well as a specimen of South American fur seal (Arctocephalus australis) with piebaldism in Uruguay. We also found 31 scientific articles resulting in 23 records of albinism, 12 of leucism, 71 of piebaldism and 92 records classified as undetermined pigmentation. Anomalous colouration is apparently rare in small terrestrial mammals, but it is much more common in cetaceans and michrochiropterans. Out of these 198 records, 149 occurred in cetaceans and 30 in bats. The results related to cetaceans suggest that males and females with anomolous pigmentation are reproductively successful and as a consequence their frequencies are becoming higher in natural populations. In bats, this result can be related to the fact these animals orient themselves primarily through echolocation, and their refuges provide protection against light and predation. It is possible that anomalous colouration occurs more frequently in other Neotropical mammal orders, which were not formally reported. Therefore, we encourage researchers to publish these events in order to better understand this phenomenon that has a significant influence on animal survival.

  20. Colour blindness.

    PubMed

    Gordon, N

    1998-03-01

    The physiology of colour vision is discussed; as is the way in which the human eye can detect various combinations of red, green and blue. Red-green colour blindness, with X-linked inheritance, is the most common, but other types are also considered. Methods of testing relating to the age of the child are reviewed. The use of colours in teaching is widespread, but there is controversy over the difficulties this may cause a colour blind child. A review of the literature does not reveal much information on this, and any problems that do arise are likely to be individual to the child, and to depend on such factors as overall intelligence, the attitude of the teacher, and the personality of the child. There is not doubt that it is essential to recognise colour vision defects when it comes to choosing a career, and that tests must be done during secondary schooling, but in order to avoid some affected children being disadvantaged there is enough evidence to support testing at school entry.

  1. Sarcocystis neurona infections in raccoons (Procyon lotor): evidence for natural infection with sarcocysts, transmission of infection to opossums (Didelphis virginiana), and experimental induction of neurologic disease in raccoons.

    PubMed

    Dubey, J P; Saville, W J; Stanek, J F; Lindsay, D S; Rosenthal, B M; Oglesbee, M J; Rosypal, A C; Njoku, C J; Stich, R W; Kwok, O C; Shen, S K; Hamir, A N; Reed, S M

    2001-10-24

    Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses in the Americas and Sarcocystis neurona is the most common etiologic agent. The distribution of S. neurona infections follows the geographical distributions of its definitive hosts, opossums (Didelphis virginiana, Didelphis albiventris). Recently, cats and skunks were reported as experimental and armadillos as natural intermediate hosts of S. neurona. In the present report, raccoons (Procyon lotor) were identified as a natural intermediate host of S. neurona. Two laboratory-raised opossums were found to shed S. neurona-like sporocysts after ingesting tongues of naturally-infected raccoons. Interferon-gamma gene knockout (KO) mice fed raccoon-opossum-derived sporocysts developed neurologic signs. S. neurona was identified immunohistochemically in tissues of KO mice fed sporocysts and the parasite was isolated in cell cultures inoculated with infected KO mouse tissues. The DNA obtained from the tongue of a naturally-infected raccoon, brains of KO mice that had neurological signs, and from the organisms recovered in cell cultures inoculated with brains of neurologic KO mice, corresponded to that of S. neurona. Two raccoons fed mature S. neurona sarcocysts did not shed sporocysts in their feces, indicating raccoons are not likely to be its definitive host. Two raccoons fed sporocysts from opossum feces developed clinical illness and S. neurona-associated encephalomyelitis was found in raccoons killed 14 and 22 days after feeding sporocysts; schizonts and merozoites were seen in encephalitic lesions.

  2. Serological evidence of exposure to tick-borne agents in opossums (Didelphis spp.) in the state of São Paulo, Brazil.

    PubMed

    Melo, Andréia Lima Tomé; Aguiar, Daniel Moura de; Spolidorio, Mariana Granziera; Yoshinari, Natalino Hajime; Matushima, Eliana Reiko; Labruna, Marcelo Bahia; Horta, Mauricio Claudio

    2016-06-07

    This work involved a serological investigation of tick-borne pathogens in opossums in eight municipalities of the state of São Paulo, Brazil. Serum samples from 109 opossums (91 Didelphis aurita and 18 Didelphis albiventris) were tested to detect antibodies to Rickettsia rickettsii (Taiaçu strain, 1:64 cut-off) and Ehrlichia canis (São Paulo strain, 1:40 cut-off), by indirect immunofluorescence assay (IFA); and against Borrelia burgdorferi (strain G39/40) by enzyme-linked immunosorbent assay (ELISA). The presence of antibodies to anti-R. rickettsii, anti-E. canis and anti-B. burgdorferi was detected in 32 (29.35%), 16 (14.67%) and 30 (27.52%) opossums, respectively. Opossum endpoint titers ranged from 64 to 1,024 for R. rickettsii, from 40 to 160 for E. canis, and from 400 to >51,200 for B. burgdorferi. These serological results suggest that opossums have been exposed to Rickettsia spp., Ehrlichia spp., and B. burgdorferi-related agents in the state of São Paulo. Our study underscores the need for further research about these agents in this study area, in view of the occurrence of Spotted Fever and Baggio-Yoshinari Syndrome disease in humans in the state of São Paulo, Brazil.

  3. Repetition blindness is orientation blind.

    PubMed

    Corballis, Michael C; Armstrong, Cole

    2007-03-01

    In identifying rapid sequences of three letters, subjects were worse at identifying the first and third letters when they were the same than when they were different, indicating repetition blindness (RB). This effect occurred regardless of the angular orientations of the letters, but was more pronounced when the orientations of the repeated letters were different than when they were the same. In a second experiment, RB was also evident when the first and third letters were lowercase bs or ds, presented upright or inverted, even though they are differently named when inverted (q and p, respectively). Conversely, a third experiment showed that RB occurred when the letters had the same names but were repeated in different case. These results suggest that the early extraction of letter shape is independent of its orientation and left-right sense, and that RB can occur at the levels of both shape and name.

  4. Action of anti-bothropic factor isolated from Didelphis marsupialis on renal effects of Bothrops erythromelas venom.

    PubMed

    Martins, Alice M C; Sousa, Fabiola C M; Barbosa, Paulo S F; Toyama, Marcos H; Toyama, Daniela O; Aprígio, Cleidiana C; Queiroz, Maria G R; Guarnieri, Mirian C; Havt, Alexandre; de Menezes, Dalgimar B; Fonteles, Manassés C; Monteiro, Helena S A

    2005-11-01

    Acute renal failure is the most common complication in the lethal cases caused by snakebites in Brazil. Among the Brazilian venom snakes, Bothrops erythromelas is responsible for the majority of accidents in Northeastern Brazil. Didelphis marsupialis serum could inhibit myonecrotic, hemorrhagic, edematogenic hyperalgesic and lethal effects of envenomation determined by ophidian bites. In the present study, we evaluated the action of the anti-bothropic factor isolated from D. marsupialis on the renal effects promoted by B. erythromelas venom without systemic interference. Isolated kidneys from Wistar rats were perfused with Krebs-Henseleit solution containing 6% bovine serum albumin. We analyzed renal perfusion pressure (PP), renal vascular resistance (RVR), glomerular filtration rate (GFR), urinary flow (UF), and the percentages of sodium and potassium tubular transport (%TNa+, %TK+). The B. erythromelas venom (10 microg mL(-1)) decreased the PP (ct = 108.71+/-5.09 mmHg; BE = 65.21+/-5.6 mmHg*) and RVR (ct = 5.76+/-0.65 mmHg mL(-1) g(-1) min(-1); BE = 3.10+/-0.45 mmHg mL(-1) g(-1) min(-1)*). On the other hand, the GFR decreased at 60 min (ct60 = 0.76+/-0.07 mL g(-1) min(-1); BE60 = 0.42+/-0.12 mL g(-1) min(-1)*) and increased at 120 min (ct120 = 0.72+/-0.01 mL g(-1) min(-1); BE120 = 1.24+/-0.26 mL g(-1) min(-1)*). The UF increased significantly when compared with the control group (ct = 0.14+/-0.01 mL g(-1) min(-1); BE = 0.47+/-0.08 mL g(-1) min(-1)*). The venom reduced the %TNa(+) (ct90 = 79.18+/-0.88%; BE90 = 58.35+/-4.86%*) and %TK+ (ct90 = 67.20+/-4.04%; BE90 = 57.32+/-5.26%*) The anti-bothropic factor from D. marsupialis (10 microg mL(-1)) incubated with B. erythromelas venom (10 microg mL(-1)) blocked the effects on PP, RVR, %TNa+, and %TK+, but was not able to reverse the effects in UF and GFR promoted by venom alone. However, the highest concentration of D. marsupialis serum (30 microg mL(-1)) reversed all the renal effects induced by the venom. In

  5. Quinine blindness.

    PubMed

    Naraqi, S; Okem, S; Moyia, N; Dutta, T K; Zzferio, B; Lalloo, D

    1992-12-01

    A young women was treated with intravenous quinine and chloramphenicol for suspected severe malaria and/or typhoid fever. On the second day of quinine therapy (after 2.25 g of quinine) she suddenly developed total bilateral loss of vision. Both drugs were stopped and cyclandelate therapy was started. She showed slight improvement in vision but on referral her visual acuity was limited to seeing waving hand movement only; visual fields were constricted and colour vision was absent. Both pupils were fixed and dilated. The fundi showed macular oedema and attenuated retinal arteries. She was treated with dexamethasone, cyclandelate, vitamin B complex and vitamin C. Colour vision was completely recovered after 5 days of treatment. Full recovery of the direct light reflex occurred after 10 days. Visual acuity improved slowly over a period of one month to 6/15 vision in both eyes. At this time macular oedema and retinal arteriolar attenuation were still present but less severe. In the context of this case report the condition of quinine blindness is briefly reviewed and the management discussed.

  6. Leishmania chagasi in Opossums (Didelphis albiventris) in an Urban Area Endemic for Visceral Leishmaniasis, Campo Grande, Mato Grosso do Sul, Brazil

    PubMed Central

    Humberg, Roberta M. P.; Oshiro, Elisa T.; Cruz, Maria do Socorro Pires e; Ribolla, Paulo E. M.; Alonso, Diego P.; Ferreira, Alda M. T.; Bonamigo, Raquel A.; Tasso, Norton; de Oliveira, Alessandra Gutierrez

    2012-01-01

    We investigated the occurrence of Leishmania infantum chagasi in Didelphis albiventris opossums at a wild animal rehabilitation center in the city of Campo Grande, Brazil. A total of 54 opossums were tested for L. i. chagasi infection in peripheral blood and bone marrow samples. The samples were analyzed by direct examination, culturing in a specific medium, and polymerase chain reaction–restriction fragment length polymorphism. Leishmania i. chagasi DNA was detected by polymerase chain reaction–restriction fragment length polymorphism in 11 (20.37%) animals. A total of 81.81% of positive opossums were captured in areas of known visceral leishmaniasis transmission. These results suggest a role for D. albiventris in the urban transmission of visceral leishmaniasis. PMID:22802435

  7. Origins of Chagas disease: Didelphis species are natural hosts of Trypanosoma cruzi I and armadillos hosts of Trypanosoma cruzi II, including hybrids.

    PubMed

    Yeo, Matthew; Acosta, Nidia; Llewellyn, Martin; Sánchez, Humberto; Adamson, Susie; Miles, Graham A J; López, Elsa; González, Nilsa; Patterson, James S; Gaunt, Michael W; de Arias, Antonieta Rojas; Miles, Michael A

    2005-02-01

    Trypanosoma cruzi, the causative agent of Chagas disease, has at least two principal intraspecific subdivisions, T. cruzi I (TCI) and T. cruzi II (TCII), the latter containing up to five subgroups (a-e). Whilst it is known that TCI predominates from the Amazon basin northwards and TCII to the South, where the disease is considered to be clinically more severe, the precise clinical and evolutionary significance of these divisions remains enigmatic. Here, we present compelling evidence of an association between TCI and opossums (Didelphis), and TCII and armadillos, on the basis of key new findings from the Paraguayan Chaco region, together with a comprehensive analysis of historical data. We suggest that the distinct arboreal and terrestrial ecologies, respectively, of these mammal hosts provide a persuasive explanation for the extant T. cruzi intraspecific diversity in South America, and for separate origins of Chagas disease in northern South America and in the southern cone countries.

  8. Representing vision and blindness.

    PubMed

    Ray, Patrick L; Cox, Alexander P; Jensen, Mark; Allen, Travis; Duncan, William; Diehl, Alexander D

    2016-01-01

    There have been relatively few attempts to represent vision or blindness ontologically. This is unsurprising as the related phenomena of sight and blindness are difficult to represent ontologically for a variety of reasons. Blindness has escaped ontological capture at least in part because: blindness or the employment of the term 'blindness' seems to vary from context to context, blindness can present in a myriad of types and degrees, and there is no precedent for representing complex phenomena such as blindness. We explore current attempts to represent vision or blindness, and show how these attempts fail at representing subtypes of blindness (viz., color blindness, flash blindness, and inattentional blindness). We examine the results found through a review of current attempts and identify where they have failed. By analyzing our test cases of different types of blindness along with the strengths and weaknesses of previous attempts, we have identified the general features of blindness and vision. We propose an ontological solution to represent vision and blindness, which capitalizes on resources afforded to one who utilizes the Basic Formal Ontology as an upper-level ontology. The solution we propose here involves specifying the trigger conditions of a disposition as well as the processes that realize that disposition. Once these are specified we can characterize vision as a function that is realized by certain (in this case) biological processes under a range of triggering conditions. When the range of conditions under which the processes can be realized are reduced beyond a certain threshold, we are able to say that blindness is present. We characterize vision as a function that is realized as a seeing process and blindness as a reduction in the conditions under which the sight function is realized. This solution is desirable because it leverages current features of a major upper-level ontology, accurately captures the phenomenon of blindness, and can be

  9. Blind Quantum Signature with Blind Quantum Computation

    NASA Astrophysics Data System (ADS)

    Li, Wei; Shi, Ronghua; Guo, Ying

    2017-04-01

    Blind quantum computation allows a client without quantum abilities to interact with a quantum server to perform a unconditional secure computing protocol, while protecting client's privacy. Motivated by confidentiality of blind quantum computation, a blind quantum signature scheme is designed with laconic structure. Different from the traditional signature schemes, the signing and verifying operations are performed through measurement-based quantum computation. Inputs of blind quantum computation are securely controlled with multi-qubit entangled states. The unique signature of the transmitted message is generated by the signer without leaking information in imperfect channels. Whereas, the receiver can verify the validity of the signature using the quantum matching algorithm. The security is guaranteed by entanglement of quantum system for blind quantum computation. It provides a potential practical application for e-commerce in the cloud computing and first-generation quantum computation.

  10. Blind Quantum Signature with Blind Quantum Computation

    NASA Astrophysics Data System (ADS)

    Li, Wei; Shi, Ronghua; Guo, Ying

    2016-12-01

    Blind quantum computation allows a client without quantum abilities to interact with a quantum server to perform a unconditional secure computing protocol, while protecting client's privacy. Motivated by confidentiality of blind quantum computation, a blind quantum signature scheme is designed with laconic structure. Different from the traditional signature schemes, the signing and verifying operations are performed through measurement-based quantum computation. Inputs of blind quantum computation are securely controlled with multi-qubit entangled states. The unique signature of the transmitted message is generated by the signer without leaking information in imperfect channels. Whereas, the receiver can verify the validity of the signature using the quantum matching algorithm. The security is guaranteed by entanglement of quantum system for blind quantum computation. It provides a potential practical application for e-commerce in the cloud computing and first-generation quantum computation.

  11. Onchocerciasis (River Blindness) FAQs

    MedlinePlus

    ... The CDC Parasites - Onchocerciasis (also known as River Blindness) Note: Javascript is disabled or is not supported ... infected Simulium blackfly. It is also called River Blindness because the fly that transmits infection breeds in ...

  12. Blindness and anorexia nervosa.

    PubMed

    McFarlane, A C

    1989-06-01

    Two cases of anorexia nervosa in blind patients are reported. They demonstrate that blind children experience many developmental problems which are thought to be important in the etiology of anorexia nervosa. Similarly, blind children are unusually susceptible to misperceive their body size and weight. The apparent absence of a strong association between congenital blindness and anorexia nervosa challenges the presumed aetiological link between disturbed body image and identity diffusion, and anorexia nervosa.

  13. Blind Loop Syndrome

    MedlinePlus

    ... breeding ground for bacteria. The bacteria may produce toxins as well as block the absorption of nutrients. The greater the length of small bowel involved in the blind loop, the greater the chance of bacterial overgrowth. What triggers blind loop syndrome? Blind loop ...

  14. Global data on blindness.

    PubMed Central

    Thylefors, B.; Négrel, A. D.; Pararajasegaram, R.; Dadzie, K. Y.

    1995-01-01

    Globally, it is estimated that there are 38 million persons who are blind. Moreover, a further 110 million people have low vision and are at great risk of becoming blind. The main causes of blindness and low vision are cataract, trachoma, glaucoma, onchocerciasis, and xerophthalmia; however, insufficient data on blindness from causes such as diabetic retinopathy and age-related macular degeneration preclude specific estimations of their global prevalence. The age-specific prevalences of the major causes of blindness that are related to age indicate that the trend will be for an increase in such blindness over the decades to come, unless energetic efforts are made to tackle these problems. More data collected through standardized methodologies, using internationally accepted (ICD-10) definitions, are needed. Data on the incidence of blindness due to common causes would be useful for calculating future trends more precisely. PMID:7704921

  15. Refractive error blindness.

    PubMed Central

    Dandona, R.; Dandona, L.

    2001-01-01

    Recent data suggest that a large number of people are blind in different parts of the world due to high refractive error because they are not using appropriate refractive correction. Refractive error as a cause of blindness has been recognized only recently with the increasing use of presenting visual acuity for defining blindness. In addition to blindness due to naturally occurring high refractive error, inadequate refractive correction of aphakia after cataract surgery is also a significant cause of blindness in developing countries. Blindness due to refractive error in any population suggests that eye care services in general in that population are inadequate since treatment of refractive error is perhaps the simplest and most effective form of eye care. Strategies such as vision screening programmes need to be implemented on a large scale to detect individuals suffering from refractive error blindness. Sufficient numbers of personnel to perform reasonable quality refraction need to be trained in developing countries. Also adequate infrastructure has to be developed in underserved areas of the world to facilitate the logistics of providing affordable reasonable-quality spectacles to individuals suffering from refractive error blindness. Long-term success in reducing refractive error blindness worldwide will require attention to these issues within the context of comprehensive approaches to reduce all causes of avoidable blindness. PMID:11285669

  16. Hemianopic colour blindness.

    PubMed

    Albert, M L; Reches, A; Silverberg, R

    1975-06-01

    A man developed cortical blindness after cerebral infarction in the distribution of both posterior cerebral arteries. When he recovered from this condition, he was found to be colour blind in the left visual field, but not in the right. This unusual situation resulted in apparently contradictory performances on hemifield and free-field tasks of colour discrimination, naming, and recognition. The contradictions may be explained by interhemispheric competition between a hemisphere which could discriminate colours and a hemisphere which was colour blind.

  17. Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozoon cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossums, Didelphis virginiana, from southern Louisiana.

    PubMed

    Houk, Alice E; Goodwin, David G; Zajac, Anne M; Barr, Stephen C; Dubey, J P; Lindsay, David S

    2010-12-01

    We examined the prevalence of antibodies to zoonotic protozoan parasites ( Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoans of veterinary importance ( Neospora caninum, Sarcocystis neurona, and Besnoitia darlingi) in a population of North American opossums ( Didelphis virginiana) from Louisiana. Samples from 30 opossums were collected as part of a survey for T. cruzi in Louisiana. Frozen sera from these 30 opossums were examined using an indirect immunofluorescent antibody test (IFAT) against in vitro-produced antigenic stages of these protozoans. Additionally, 24 of the 30 samples were examined using hemoculture, and all 30 were examined in the modified direct agglutination test (MAT) for antibodies to To. gondii. The prevalences of reactive IFAT samples were as follows: 60% for T. cruzi, 27% for To. gondii, 23% for E. cuniculi, 17% for S. neurona, 47% for B. darlingi, and 0% for N. caninum. Hemoculture revealed that 16 (67%) of 24 samples were positive for T. cruzi, compared to 18 of 30 (60%) by IFAT. The sensitivity and specificity for the IFAT compared to hemoculture was 100% for each. The modified direct agglutination test revealed that 9 (30%) of the 30 samples from opossums had antibodies to To. gondii , compared to 8 (27%) using the IFAT. The sensitivity and specificity of the IFAT compared to the MAT was 100% and 72%, respectively.

  18. Sarcocystis neurona infections in sea otter (Enhydra lutris): evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana)

    USGS Publications Warehouse

    Dubey, J.P.; Rosypal, A.C.; Rosenthal, B.M.; Thomas, N.J.; Lindsay, D.S.; Stanek, J.F.; Reed, S.M.; Saville, W.J.A.

    2001-01-01

    Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 I?m long, and the villar protrusions on the sarcocyst wall were up to 1.3 I?m long and up to 0.25 I?m wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts. Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.

  19. Eosinophilic meningoencephalitis associated with rat lungworm (Angiostrongylus cantonensis) migration in two nine-banded armadillos (Dasypus novemcinctus) and an opossum (Didelphis virginiana) in the southeastern United States.

    PubMed

    Dalton, Martha F; Fenton, Heather; Cleveland, Christopher A; Elsmo, Elizabeth J; Yabsley, Michael J

    2017-08-01

    Angiostrongylus cantonensis, the rat lungworm, was the cause of neural larval migrans in two nine-banded armadillos (Dasypus novemcinctus) and one Virginia opossum (Didelphis virginiana) from the southeastern United States. Histologic findings in all three cases included eosinophilic meningoencephalitis with variable numbers of nematode larvae in the meninges or the neuroparenchyma. In two of the three cases, nematodes were extracted from brain tissue via a "squash prep" method. Identification of the nematodes was confirmed by amplification and sequence analysis of the partial cytochrome c oxidase subunit I gene from all three cases. Sequences (704bp) from the two cases from Louisiana were identical and 99.7% similar to nematodes detected in the armadillo from Florida. As A. cantonensis is now considered endemic in the southern United States, it should be considered as an important differential for any wild or domestic animal or human patient with neurological signs and eosinophilic meningitis. Many wildlife species frequently consume snails and slugs and could serve as sentinels for the detection of this parasite in regions where the presence of this parasite has not been confirmed. To the authors' knowledge, this is the first report of neural larval migrans due to A. cantonensis in an armadillo and provides additional documentation that this nematode can cause disease in wildlife species in the southeastern United States.

  20. Establishment of Besnoitia darlingi from opossums (Didelphis virginiana) in experimental intermediate and definitive hosts, propagation in cell culture, and description of ultrastructural and genetic characteristics.

    PubMed

    Dubey, J P; Lindsay, D S; Rosenthal, B M; Sreekumar, C; Hill, D E; Shen, S K; Kwok, O C H; Rickard, L G; Black, S S; Rashmir-Raven, A

    2002-07-01

    Besnoitia darlingi from naturally infected opossums (Didelphis virginiana) from Mississippi, USA, was propagated experimentally in mice, cats, and cell culture and was characterised according to ultrastructural, genetic, and life-history characteristics. Cats fed tissue cysts from opossums shed oocysts with a prepatent period of nine or 11 days. Oocysts, bradyzoites, or tachyzoites were infective to outbred and interferon-gamma gene knockout mice. Tachyzoites were successfully cultivated and maintained in vitro in bovine monocytes and African green monkey cells and revived after an 18-month storage in liquid nitrogen. Schizonts were seen in the small intestinal lamina propria of cats fed experimentally-infected mouse tissues. These schizonts measured up to 45 x 25 microm and contained many merozoites. A few schizonts were present in mesenteric lymph nodes and livers of cats fed tissue cysts. Ultrastructurally, tachyzoites and bradyzoites of B. darlingi were similar to other species of Besnoitia. A close relationship to B. besnoiti and an even closer relationship to B. jellisoni was indicated for B. darlingi on the basis of the small subunit and ITS-1 portions of nuclear ribosomal DNA.

  1. "Color-Blind" Racism.

    ERIC Educational Resources Information Center

    Carr, Leslie G.

    Examining race relations in the United States from a historical perspective, this book explains how the constitution is racist and how color blindness is actually a racist ideology. It is argued that Justice Harlan, in his dissenting opinion in Plessy v. Ferguson, meant that the constitution and the law must remain blind to the existence of race…

  2. Blindness after intranasal ethmoidectomy.

    PubMed

    Sözeri, B; Ataman, M; Gürsel, B

    1993-06-01

    Orbital haemorrhage is an unusual and frustrating complication of ethmoid surgery. A case of reversible blindness which was due to intra-operative orbital haemorrhage occurring after intranasal ethmoidectomy is presented. Prevention and management of this kind of blindness can be reversed, if treated aggressively.

  3. "Color-Blind" Racism.

    ERIC Educational Resources Information Center

    Carr, Leslie G.

    Examining race relations in the United States from a historical perspective, this book explains how the constitution is racist and how color blindness is actually a racist ideology. It is argued that Justice Harlan, in his dissenting opinion in Plessy v. Ferguson, meant that the constitution and the law must remain blind to the existence of race…

  4. Blindness and Yoga

    ERIC Educational Resources Information Center

    Heyes, Anthony David

    1974-01-01

    Evidence is presented to support the claims that, among many blind persons, physical inactivity leads to poor physical fitness; that a state of anxiety is often a concomitant of unguided blind mobility; and that Yogic practices offer a solution to both difficulties. (GW)

  5. Change blindness images.

    PubMed

    Ma, Li-Qian; Xu, Kun; Wong, Tien-Tsin; Jiang, Bi-Ye; Hu, Shi-Min

    2013-11-01

    Change blindness refers to human inability to recognize large visual changes between images. In this paper, we present the first computational model of change blindness to quantify the degree of blindness between an image pair. It comprises a novel context-dependent saliency model and a measure of change, the former dependent on the site of the change, and the latter describing the amount of change. This saliency model in particular addresses the influence of background complexity, which plays an important role in the phenomenon of change blindness. Using the proposed computational model, we are able to synthesize changed images with desired degrees of blindness. User studies and comparisons to state-of-the-art saliency models demonstrate the effectiveness of our model.

  6. Blinded by Irrelevance: Pure Irrelevance Induced "Blindness"

    ERIC Educational Resources Information Center

    Eitam, Baruch; Yeshurun, Yaffa; Hassan, Kinneret

    2013-01-01

    To what degree does our representation of the immediate world depend solely on its relevance to what we are currently doing? We examined whether relevance per se can cause "blindness," even when there is no resource limitation. In a novel paradigm, people looked at a colored circle surrounded by a differently colored ring--the task relevance of…

  7. Blinded by Irrelevance: Pure Irrelevance Induced "Blindness"

    ERIC Educational Resources Information Center

    Eitam, Baruch; Yeshurun, Yaffa; Hassan, Kinneret

    2013-01-01

    To what degree does our representation of the immediate world depend solely on its relevance to what we are currently doing? We examined whether relevance per se can cause "blindness," even when there is no resource limitation. In a novel paradigm, people looked at a colored circle surrounded by a differently colored ring--the task relevance of…

  8. How "Blind" Are Double-Blind Studies?

    ERIC Educational Resources Information Center

    Margraf, Jurgen; And Others

    1991-01-01

    Compared alprazolam, imipramine, and placebo in the treatment of panic disorder patients (n=59) to investigate concerns about the internal validity of the double-blind design. Found that the great majority of patients and physicians were able to rate accurately whether active drug or placebo had been given and physicians could distinguish between…

  9. Which Factors Determine Spatial Segregation in the South American Opossums (Didelphis aurita and D. albiventris)? An Ecological Niche Modelling and Geometric Morphometrics Approach

    PubMed Central

    Cáceres, Nilton Carlos; de Moraes Weber, Marcelo; Melo, Geruza Leal; Meloro, Carlo; Sponchiado, Jonas; Carvalho, Renan dos Santos; Bubadué, Jamile de Moura

    2016-01-01

    Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allopatric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology. For this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might share their geographic space. Little is known about how two morphologically similar species of marsupials may affect each other through competition, if by competitive exclusion and competitive release. We combined ecological niche modeling and geometric morphometrics to explore the possible effects of competition on their distributional ranges and skull morphology. Ecological niche modeling was used to predict their potential distribution and this method enabled us to identify a case of biotic exclusion where the habit generalist D. albiventris is excluded by the presence of the specialist D. aurita. The morphometric analyses show that a degree of shape discrimination occurs between the species, strengthened by allometric differences, which possibly allowed them to occupy marginally different feeding niches supplemented by behavioral shift in contact areas. Overlap in skull morphology is shown between sympatric and allopatric specimens and a significant, but weak, shift in shape occurs only in D. aurita in sympatric areas. This could be a residual evidence of a higher past competition between both species, when contact zones were possibly larger than today. Therefore, the specialist D. aurita acts a biotic barrier to D. albiventris when niche diversity is not available for coexistence. On the other hand, when there is niche diversification (e.g. habitat mosaic), both species are capable to coexist with a minimal competitive effect on the morphology of D. aurita. PMID

  10. Prevalence of and risk factors associated with the presence of Sarcocystis neurona sporocysts in opossum (Didelphis virginiana) from Michigan: a retrospective study.

    PubMed

    Elsheikha, Hany M; Murphy, Alice J; Mansfield, Linda S

    2004-11-10

    From April 1996 to December 2002 the prevalence of Sarcocystis neurona sporocysts in North American opossum (Didelphis virginiana) in Southern Michigan was estimated. Sporocysts of S. neurona were found in intestinal scrapings from 31 (15%) of 206 examined opossum. The frequency of infection was higher in adult animals (26/206; 12.6%) and females (19/206; 9.2%) than in juveniles (5/206; 2.4%) and males (12/206; 5.8%). Also, prevalence of S. neurona sporocysts in opossums in relation to factors such as age, sex, season, body condition, presence of concomitant infection, and presence of young in the pouch of females was studied in detail over the course of the year, 2002. Univariate analyses identified the following factors as being associated with the presence of S. neurona sporocysts in opossums: (i) for age, adult (odd ratio [OR] = 2.074, P = 0.0005); (ii) for sex, female (OR = 7.016, P = 0.0119); (iii) for season, summer (OR = 7.917, P = 0.0032) and spring (OR = 4.071, P = 0.1063); (iv) for body condition, poor (OR = 3.50, P = 0.1200) and good (OR = 1.167, P = 0.8637); (v) for the presence of concomitant infection (OR = 23.056, P = 0001), and (vi) for the presence of young in the pouch of females (OR = 40.083, P = 0.0001). Multivariate logistic-regression analyses selected the following factors as being significantly associated with presence of S. neurona sporocysts in opossums: (i) for the presence of concomitant infection (OR = 8.722, P = 0.0160) and (ii) for the presence of young in the pouch of females (OR = 31.915, P = 0.0065). The prevalence of S. neurona sporocysts in D. virginiana suggests that this opossum may constitute an ample reservoir of infection to other animals in the northern United States.

  11. Which Factors Determine Spatial Segregation in the South American Opossums (Didelphis aurita and D. albiventris)? An Ecological Niche Modelling and Geometric Morphometrics Approach.

    PubMed

    Cáceres, Nilton Carlos; de Moraes Weber, Marcelo; Melo, Geruza Leal; Meloro, Carlo; Sponchiado, Jonas; Carvalho, Renan Dos Santos; Bubadué, Jamile de Moura

    2016-01-01

    Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allopatric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology. For this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might share their geographic space. Little is known about how two morphologically similar species of marsupials may affect each other through competition, if by competitive exclusion and competitive release. We combined ecological niche modeling and geometric morphometrics to explore the possible effects of competition on their distributional ranges and skull morphology. Ecological niche modeling was used to predict their potential distribution and this method enabled us to identify a case of biotic exclusion where the habit generalist D. albiventris is excluded by the presence of the specialist D. aurita. The morphometric analyses show that a degree of shape discrimination occurs between the species, strengthened by allometric differences, which possibly allowed them to occupy marginally different feeding niches supplemented by behavioral shift in contact areas. Overlap in skull morphology is shown between sympatric and allopatric specimens and a significant, but weak, shift in shape occurs only in D. aurita in sympatric areas. This could be a residual evidence of a higher past competition between both species, when contact zones were possibly larger than today. Therefore, the specialist D. aurita acts a biotic barrier to D. albiventris when niche diversity is not available for coexistence. On the other hand, when there is niche diversification (e.g. habitat mosaic), both species are capable to coexist with a minimal competitive effect on the morphology of D. aurita.

  12. Experimental infection of opossums Didelphis aurita by Rickettsia rickettsii and evaluation of the transmission of the infection to ticks Amblyomma cajennense.

    PubMed

    Horta, Maurício C; Moraes-Filho, Jonas; Casagrande, Renata A; Saito, Tais B; Rosa, Simone C; Ogrzewalska, Maria; Matushima, Eliana R; Labruna, Marcelo B

    2009-02-01

    The present study evaluated the infection of opossums (Didelphis aurita) by Rickettsia rickettsii and their role as amplifier hosts for horizontal transmission of R. rickettsii to Amblyomma cajennense ticks. Three groups of opossums were evaluated: on day 0, group 1 (G1) was inoculated intraperitoneally with R. rickettsii; group 2 (G2) was infested by R. rickettsii-infected ticks; and group 3 (G3) was the uninfected control group. Opossum rectal temperature was measured daily. Blood samples were collected every 2 to 4 days during 30 days, and used to (1) inoculate guinea pigs intraperitoneally; (2) extract DNA followed by real-time polymerase chain reaction (PCR) targeting the rickettsial gene gltA; (3) study hematology; (4) detect R. rickettsii-reactive antibodies by indirect immunofluorescence assay (IFA). Blood was also collected every 10 days from days 30 to 180, to be tested by serology. Opossums were infested by uninfected A. cajennense larvae and nymphs from days 3 to 15. Engorged ticks were collected and allowed to molt in an incubator. Thereafter, the subsequent flat ticks were allowed to feed on uninfected rabbits, which were tested for seroconversion by IFA. Samples of flat ticks were also tested by real-time PCR. All G1 and G2 opossums became infected by R. rickettsii, as demonstrated by realtime PCR or/and guinea pig inoculation, but they showed no clinical abnormality. Rickettsemia was first detected at days 2 to 8, lasting intermittently till days 1 to 30. Approximately 18% and 5% of the flat ticks previously fed on G1 and G2 opossums, respectively, became infected by R. rickettsii, but only the rabbits infested with G1-derived ticks seroconverted. The study demonstrated that R. rickettsii was capable of infecting opossums without causing illness and developing rickettsemia capable of causing infection in guinea pigs and ticks, although the infection rate in ticks was low.

  13. Quantification of endocrine cells and ultrastructural study of insulin granules in the large intestine of opossum Didelphis aurita (Wied-Neuwied, 1826).

    PubMed

    dos Santos, Daiane Cristina Marques; Cupertino, Marli do Carmo; Fialho, Maria do Carmo Queiroz; Barbosa, Alfredo Jose Afonso; Fonseca, Cláudio Cesar; Sartori, Sirlene Souza Rodrigues; da Matta, Sérgio Luis Pinto

    2014-02-01

    This study aimed to investigate the distribution of argyrophil, argentaffin, and insulin-immunoreactive endocrine cells in the large intestine of opossums (Didelphis aurita) and to describe the ultrastructure of the secretory granules of insulin-immunoreactive endocrine cells. Fragments of the large intestine of 10 male specimens of D. aurita were collected, processed, and subjected to staining, immunohistochemistry, and transmission electron microscopy. The argyrophil, the argentaffin, and the insulin-immunoreactive endocrine cells were sparsely distributed in the intestinal glands of the mucous layer, among other cell types of the epithelium in all regions studied. Proportionally, the argyrophil, the argentaffin, and the insulin-immunoreactive endocrine cells represented 62.75%, 36.26%, and 0.99% of the total determined endocrine cells of the large intestine, respectively. Quantitatively, there was no difference between the argyrophil and the argentaffin endocrine cells, whereas insulin-immunoreactive endocrine cells were less numerous. The insulin-immunoreactive endocrine cells were elongated or pyramidal, with rounded nuclei of irregularly contoured, and large amounts of secretory granules distributed throughout the cytoplasm. The granules have different sizes and electron densities and are classified as immature and mature, with the mature granules in predominant form in the overall granular population. In general, the granule is shown with an external electron-lucent halo and electron-dense core. The ultrastructure pattern in the granules of the insulin-immunoreactive endocrine cells was similar to that of the B cells of pancreatic islets in rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Hemianopic colour blindness.

    PubMed Central

    Albert, M L; Reches, A; Silverberg, R

    1975-01-01

    A man developed cortical blindness after cerebral infarction in the distribution of both posterior cerebral arteries. When he recovered from this condition, he was found to be colour blind in the left visual field, but not in the right. This unusual situation resulted in apparently contradictory performances on hemifield and free-field tasks of colour discrimination, naming, and recognition. The contradictions may be explained by interhemispheric competition between a hemisphere which could discriminate colours and a hemisphere which was colour blind. PMID:1080190

  15. Leading Causes of Blindness

    MedlinePlus

    ... Cataract. Photo courtesy of National Eye Institute, NIH Cataracts Cataracts are a clouding of the lenses in your ... older people. More than 22 million Americans have cataracts. They are the leading cause of blindness in ...

  16. Facts About Color Blindness

    MedlinePlus

    ... visual function, preservation of sight, and the special health problems and requirements of the blind.” News & Events Events Calendar NEI Press Releases News from NEI Grantees Spokesperson bios Statistics and ... Frequently asked questions Clinical Studies Publications Catalog ...

  17. What is Color Blindness?

    MedlinePlus

    ... three color cone cells to determine our color perception. Color blindness can occur when one or more ... Anyone who experiences a significant change in color perception should see an ophthalmologist (Eye M.D.). Next ...

  18. Color Blindness Simulations

    MedlinePlus

    ... gov Site Map News Organization Search NWS All NOAA Home Why build an accessible web? How many ... Updates, additions Contact Us For assistance contact your NOAA Line Office Section 508 Coordinator Color blindness Simulations ...

  19. Adjustment to Blindness

    ERIC Educational Resources Information Center

    Delafield, George L.

    1976-01-01

    The author examines various factors that can or should be used to determine adjustment to a disability such as blindness and discusses the need for developing ways to accurately measure the process. (Author)

  20. Epidemiology of blindness in Nepal*

    PubMed Central

    Brilliant, L. B.; Pokhrel, R. P.; Grasset, N. C.; Lepkowski, J. M.; Kolstad, A.; Hawks, W.; Pararajasegaram, R.; Brilliant, G. E.; Gilbert, S.; Shrestha, S. R.; Kuo, J.

    1985-01-01

    This report presents the major findings of the Nepal Blindness Survey, the first nationwide epidemiological survey of blindness, which was conducted in 1979-80. The survey was designed to gather data that could be used to estimate the prevalence and causes of blindness in the country. Ancillary studies were conducted to obtain information on socioeconomic correlates and other risk factors of blinding conditions and patterns of health care utilization. The nationwide blindness prevalence rate is 0.84%. Cataract is the leading cause of blindness, accounting for over 80% of all avoidable blindness. Trachoma is the most prevalent blinding condition, affecting 6.5% of the population. Very few cases of childhood blindness were detected. The implications of the survey findings for programme planning, health manpower development, and health education are discussed. PMID:3874717

  1. In vivo strains in the femur of the Virginia opossum (Didelphis virginiana) during terrestrial locomotion: testing hypotheses of evolutionary shifts in mammalian bone loading and design.

    PubMed

    Butcher, Michael T; White, Bartholomew J; Hudzik, Nathan B; Gosnell, W Casey; Parrish, John H A; Blob, Richard W

    2011-08-01

    Terrestrial locomotion can impose substantial loads on vertebrate limbs. Previous studies have shown that limb bones from cursorial species of eutherian mammals experience high bending loads with minimal torsion, whereas the limb bones of non-avian reptiles (and amphibians) exhibit considerable torsion in addition to bending. It has been hypothesized that these differences in loading regime are related to the difference in limb posture between upright mammals and sprawling reptiles, and that the loading patterns observed in non-avian reptiles may be ancestral for tetrapod vertebrates. To evaluate whether non-cursorial mammals show loading patterns more similar to those of sprawling lineages, we measured in vivo strains in the femur during terrestrial locomotion of the Virginia opossum (Didelphis virginiana), a marsupial that uses more crouched limb posture than most mammals from which bone strains have been recorded, and which belongs to a clade phylogenetically between reptiles and the eutherian mammals studied previously. The presence of substantial torsion in the femur of opossums, similar to non-avian reptiles, would suggest that this loading regime likely reflects an ancestral condition for tetrapod limb bone design. Strain recordings indicate the presence of both bending and appreciable torsion (shear strain: 419.1 ± 212.8 με) in the opossum femur, with planar strain analyses showing neutral axis orientations that placed the lateral aspect of the femur in tension at the time of peak strains. Such mediolateral bending was unexpected for a mammal running with near-parasagittal limb kinematics. Shear strains were similar in magnitude to peak compressive axial strains, with opossum femora experiencing similar bending loads but higher levels of torsion compared with most previously studied mammals. Analyses of peak femoral strains led to estimated safety factor ranges of 5.1-7.2 in bending and 5.5-7.3 in torsion, somewhat higher than typical mammalian values

  2. Blinded by headlights.

    PubMed

    Stevanovski, Biljana; Oriet, Chris; Jolicoeur, Pierre

    2002-06-01

    Target identification is impaired when targets are presented during the planning or execution of a compatible response (e.g., right-pointing arrow during a right keypress) relative to an incompatible response (Müsseler & Hommel, 1997 a, b). Examinations of this blindness to response-compatible stimuli have typically used arrowheads as targets ("<" and ">"). The importance of the target symbol was examined by manipulating subjects' interpretation of that symbol (i.e., ">" interpreted as a right-pointing arrow or as a headlight shining to the left). Targets were presented at varying times during the planning or execution of a response in order to examine the time-course of the effect. Results showed that the interpretation, and not the physical identity, of the target was important for the blindness effect. Although the blindness effect was largest during the planning and execution of a response, it was not always confined to that temporal interval.

  3. Meningeal carcinomatosis and blindness

    PubMed Central

    Altrocchi, Paul H.; Eckman, Paul B.

    1973-01-01

    The clinical syndrome of meningeal carcinomatosis includes headache, dementia, radiculopathy, and cranial nerve palsies. Blindness may be the first, or most prominent, symptom. When blindness occurs in adult life, meningeal carcinomatosis should be included in the differential diagnosis, even in the absence of other symptoms and in the absence of known malignancy. Although all pathophysiological mechanisms of the blindness in meningeal carcinomatosis have not yet been elucidated, optic nerve involvement by meningeal tumour-cuffing, by chronic papilloedema, and by direct tumour infiltration represent the likeliest causes. In the neuropathological analysis of such cases, the importance of analysing the intra-orbital portion of the optic nerves, in addition to the portions of the optic nerve and chiasm usually examined at routine necropsy, is emphasized. A case is described to illustrate this point, with the only pathological abnormality in the optic nerves being found within 6 mm of the retina. Images PMID:4708455

  4. Optimal Blind Quantum Computation

    NASA Astrophysics Data System (ADS)

    Mantri, Atul; Pérez-Delgado, Carlos A.; Fitzsimons, Joseph F.

    2013-12-01

    Blind quantum computation allows a client with limited quantum capabilities to interact with a remote quantum computer to perform an arbitrary quantum computation, while keeping the description of that computation hidden from the remote quantum computer. While a number of protocols have been proposed in recent years, little is currently understood about the resources necessary to accomplish the task. Here, we present general techniques for upper and lower bounding the quantum communication necessary to perform blind quantum computation, and use these techniques to establish concrete bounds for common choices of the client’s quantum capabilities. Our results show that the universal blind quantum computation protocol of Broadbent, Fitzsimons, and Kashefi, comes within a factor of (8)/(3) of optimal when the client is restricted to preparing single qubits. However, we describe a generalization of this protocol which requires exponentially less quantum communication when the client has a more sophisticated device.

  5. [Blindness and visual rehabilitation].

    PubMed

    Matonti, F; Roux, S; Denis, D; Picaud, S; Chavane, F

    2015-02-01

    Blindness and visual impairment are a major public health problem all over the world and in all societies. A large amount of basic science and clinical research aims to rehabilitate patients and help them become more independent. Various methods are explored from cell and molecular therapy to prosthetic interfaces. We review the various treatment alternatives, describing their results and their limitations.

  6. Blindness in the Toybox

    ERIC Educational Resources Information Center

    Swartz, Edward M.

    1973-01-01

    The author proposes that toys which have been shown to cause blindness (such as dart guns, bows and arrows, peashooters, air guns, and slingshots) be banned, and suggests that government regulatory agencies and the toy industry have been lax in acting on their expressed concern for safety. (DB)

  7. Homer: The Blind Bard

    ERIC Educational Resources Information Center

    Doorley, Rachelle; King, Judith

    2005-01-01

    This article describes notable cultural, historical, and artistic elements emanating from sculptures originating in ancient Greece. The "blind bard" and its connection to the legendary Greek poet, Homer; Homer's impact on literary history; trends among Roman sculptures; and Roman replication of Greek art are described. Questions to…

  8. The blind beautiful eye.

    PubMed

    Feinsod, M

    2000-03-01

    Master Jehan Yperman, a medieval surgeon, observed that when the optic nerve is injured, the eye becomes blind and beautiful. This is an attempt to trace the footsteps of this forgotten surgeon and to track the history of the cosmetic use of the belladonna herb, as well as the concept of amaurotic mydriasis.

  9. On Simulating Blindness.

    ERIC Educational Resources Information Center

    Kappan, David

    Many educators in facilitative roles have approached the subject of visual disabilities by constructing activities designed to simulate blindness, using a blindfold or similar device. Participants are subsequently encouraged to perform rudimentary tasks such as eating a meal or moving about with a sighted companion as a guide. Frequently,…

  10. Folklore of Blindness.

    ERIC Educational Resources Information Center

    Wagner-Lampl, A.; Oliver, G. W.

    1994-01-01

    This article uses both case examples and reports from archives and oral literature to illustrate the broad range of connections between blindness and superstitions, folklore, beliefs, and mythology. Clinicians are urged to be aware of these beliefs as they counsel individuals adapting to the loss of vision. (Author/DB)

  11. Blinded by Science.

    ERIC Educational Resources Information Center

    Snyder, Tom

    1994-01-01

    Huge infusion of technology is coming into education; nothing can stop it, because so much money is involved. With computer marketers in driver seat instead of teachers, schools risk being blinded by science. Vendors have coopted progressive education buzzwords, including "frontal teaching,""linear thinking," and "computer…

  12. Homer: The Blind Bard

    ERIC Educational Resources Information Center

    Doorley, Rachelle; King, Judith

    2005-01-01

    This article describes notable cultural, historical, and artistic elements emanating from sculptures originating in ancient Greece. The "blind bard" and its connection to the legendary Greek poet, Homer; Homer's impact on literary history; trends among Roman sculptures; and Roman replication of Greek art are described. Questions to…

  13. Testing Children for Color Blindness

    MedlinePlus

    ... blindness as soon as age 4, finds Caucasian boys most likely to be color blind among different ... age 4. In addition, researchers found that Caucasian boys have the highest prevalence among four major ethnicities, ...

  14. Cognitive Mapping by the Blind.

    ERIC Educational Resources Information Center

    Casey, Steven M.

    1978-01-01

    In an effort to study the cognitive mapping abilities of blind persons, tactile maps of a school campus were made by ten congenitally blind and ten blindfolded partially sighted high school students. (Author)

  15. Sighted Children Learn About Blindness

    ERIC Educational Resources Information Center

    Scheffers, Wenda L.

    1977-01-01

    In a 20-lesson unit, sighted second-to fourth-grade students were taught about the long cane, guide dogs, daily living skills, eye physiology, causes of blindness, eye care, braille, and attitudes toward blindness. (CL)

  16. Sighted Children Learn About Blindness

    ERIC Educational Resources Information Center

    Scheffers, Wenda L.

    1977-01-01

    In a 20-lesson unit, sighted second-to fourth-grade students were taught about the long cane, guide dogs, daily living skills, eye physiology, causes of blindness, eye care, braille, and attitudes toward blindness. (CL)

  17. Corneal blindness and xenotransplantation.

    PubMed

    Lamm, Vladimir; Hara, Hidetaka; Mammen, Alex; Dhaliwal, Deepinder; Cooper, David K C

    2014-01-01

    Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

  18. CORNEAL BLINDNESS AND XENOTRANSPLANTATION

    PubMed Central

    Lamm, Vladimir; Hara, Hidetaka; Mammen, Alex; Dhaliwal, Deepinder; Cooper, David K.C.

    2014-01-01

    Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world’s blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies among parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty (ALK), and endothelial keratoplasty (EK). Indications for corneal transplantation vary among countries, with Fuchs’ dystrophy being the leading indication in the U.S. and keratoconus in Australia. With the exception of the US, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, e.g., stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically-engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future. PMID:25268248

  19. Programs for the Deaf Blind.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1987

    1987-01-01

    The directory lists 30 programs for deaf-blind children and youth, the 10 regional offices of the Helen Keller National Center for Deaf-Blind Youths and Adults, and five programs for training teachers of the deaf-blind. Provided for each program is address, director's name, and phone number. (DB)

  20. [The blindness in the literature-Jose Saramago: blindness and Albert Bang: the blind witness].

    PubMed

    Permin, H; Norn, M

    2001-01-01

    Two novels with different aspects of blindness seen through the doctors eyes. The Portuguese Nobel-prize winner José Saramago's story of a city struck by an epidemic of "white blindness", where the truth is what we cannot bear to see. The Danish author and unskilled labourer Albert Bang's (synonym with Karl E. Rasmussen) crime novel describes a blind or pretend to be blind butcher, who is a witness to a murder. Both novels are lyric, thought-provoking and insightful.

  1. Gene therapy for blindness.

    PubMed

    Sahel, José-Alain; Roska, Botond

    2013-07-08

    Sight-restoring therapy for the visually impaired and blind is a major unmet medical need. Ocular gene therapy is a rational choice for restoring vision or preventing the loss of vision because most blinding diseases originate in cellular components of the eye, a compartment that is optimally suited for the delivery of genes, and many of these diseases have a genetic origin or genetic component. In recent years we have witnessed major advances in the field of ocular gene therapy, and proof-of-concept studies are under way to evaluate the safety and efficacy of human gene therapies. Here we discuss the concepts and recent advances in gene therapy in the retina. Our review discusses traditional approaches such as gene replacement and neuroprotection and also new avenues such as optogenetic therapies. We conjecture that advances in gene therapy in the retina will pave the way for gene therapies in other parts of the brain.

  2. Blind digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Anderson, Patrick N.; Wiegandt, Florian; Treacher, Daniel J.; Mang, Matthias M.; Gianani, Ilaria; Schiavi, Andrea; Lloyd, David T.; O'Keeffe, Kevin; Hooker, Simon M.; Walmsley, Ian A.

    2017-03-01

    A blind variant of digital holographic microscopy is presented that removes the requirement for a well-characterized, highly divergent reference beam. This is achieved by adopting an off-axis recording geometry where a sequence of holograms is recorded as the reference is tilted, and an iterative algorithm that estimates the amplitudes and phases of both beams while simultaneously enhancing the numerical aperture. Numerical simulations have demonstrated the accuracy and robustness of this approach when applied to the coherent imaging problem.

  3. Blind shaft development

    SciTech Connect

    Fiscor, S.

    2009-02-15

    The article discusses how Shaft Drillers International (SDI) is breaking new ground in shaft development and ground stabilization. Techniques of blind shaft drilling and raise bore shaft development developed by SDI are briefly explained. An associated company, Coastal Drilling East, deals with all types of ground improvement such as pre-grouting work for shafts, grouting of poor soil and water leaks into the mine. 3 photos.

  4. Geometry of blind thrusts

    SciTech Connect

    Kligfield, R.; Geiser, P.; Geiser, J.

    1985-01-01

    Blind thrusts are structures which at no time in their history broke the erosion surface and along which displacement progressively changes upwards. Faults of the stiff layer along which displacement progressively decreases to zero (tip) are one prominent type of blind thrust structure. Shortening above such tips is accommodated entirely by folding whereas shortening below the tip is partitioned between folding and faulting. For these types of faults it is possible to determine the original length of the stiff layer for balancing purposes. A systematic methodology for line length and area restoration is outlined for determining blind thrust geometry. Application of the methodology is particularly suitable for use with microcomputers. If the folded form of the cover is known along with the position of the fault and its tip, then it is possible to locate hanging and footwall cutoffs. If the fault trajectory, tip, and a single hanging wall footwall cutoff pair are known, then the folded form of the cover layer can be determined. In these constructions it is necessary to specify pin lines for balancing purposes. These pin lines may or may not have a zero displacement gradient, depending upon the amount of simple shear deformation. Examples are given from both Laramide structures of the western USA and the Appalachians.

  5. Unsupervised Blind Deconvolution

    NASA Astrophysics Data System (ADS)

    Baena-Galle, R.; Kann, L.; Mugnier, L.; Gudimetla, R.; Johnson, R.; Gladysz, S.

    2013-09-01

    "Blind" deconvolution is rarely executed blindly. All available methods have parameters which the user fine-tunes until the most visually-appealing reconstruction is achieved. The "art" of deconvolution is to find constraints which allow for the best estimate of an object to be recovered, but in practice these parameterized constraints often reduce deconvolution to the struggle of trial and error. In the course of AFOSR-sponsored activities we are developing a general maximum a posteriori framework for the problem of imaging through atmospheric turbulence, with the emphasis on multi-frame blind deconvolution. Our aim is to develop deconvolution strategy which is reference-less, i.e. no calibration PSF is required, extendable to longer exposures, and applicable to imaging with adaptive optics. In the first part of the project the focus has been on developing a new theory of statistics of images taken through turbulence, both with-, and without adaptive optics. Images and their Fourier transforms have been described as random phasor sums, their fluctuations controlled by wavefront "cells" and moments of the phase. The models were validated using simulations and real data from the 3.5m telescope at the Starfire Optical Range in New Mexico. Another important ingredient of the new framework is the capability to estimate the average PSF automatically from the target observations. A general approach, applicable to any type of object, has been proposed. Here use is made of an object-cancelling transformation of the image sequence. This transformation yields information about the atmospheric PSF. Currently, the PSF estimation module and the theoretical constraints on PSF variability are being incorporated into multi-frame blind deconvolution. In preliminary simulation tests we obtained significantly sharper images with respect to the starting observations and PSF estimates which closely track the input kernels. Thanks to access to the SOR 3.5m telescope we are now testing

  6. Fighting blindness with microelectronics.

    PubMed

    Zrenner, Eberhart

    2013-11-06

    There is no approved cure for blindness caused by degeneration of the photoreceptor cells of the retina. However, there has been encouraging progress with attempts to restore vision using microelectronic retinal implant devices. Yet many questions remain to be addressed. Where is the best location to implant multielectrode arrays? How can spatial and temporal resolution be improved? What are the best ways to ensure the safety and longevity of these devices? Will color vision be possible? This Perspective discusses the current state of the art of retinal implants and attempts to address some of the outstanding questions.

  7. Multiscale image blind denoising.

    PubMed

    Lebrun, Marc; Colom, Miguel; Morel, Jean-Michel

    2015-10-01

    Arguably several thousands papers are dedicated to image denoising. Most papers assume a fixed noise model, mainly white Gaussian or Poissonian. This assumption is only valid for raw images. Yet, in most images handled by the public and even by scientists, the noise model is imperfectly known or unknown. End users only dispose the result of a complex image processing chain effectuated by uncontrolled hardware and software (and sometimes by chemical means). For such images, recent progress in noise estimation permits to estimate from a single image a noise model, which is simultaneously signal and frequency dependent. We propose here a multiscale denoising algorithm adapted to this broad noise model. This leads to a blind denoising algorithm which we demonstrate on real JPEG images and on scans of old photographs for which the formation model is unknown. The consistency of this algorithm is also verified on simulated distorted images. This algorithm is finally compared with the unique state of the art previous blind denoising method.

  8. Deaf, blind or deaf-blind: Is touch enhanced?

    PubMed

    Papagno, Costanza; Cecchetto, Carlo; Pisoni, Alberto; Bolognini, Nadia

    2016-02-01

    When someone looses one type of sensory input, s/he may compensate by using the sensory information conveyed by other senses. To verify whether loosing a sense or two has consequences on a spared sensory modality, namely touch, and whether these consequences depend on the type of sensory loss, we investigated the effects of deafness and blindness on temporal and spatial tactile tasks in deaf, blind and deaf-blind people. Deaf and deaf-blind people performed the spatial tactile task better than the temporal one, while blind and controls showed the opposite pattern. Deaf and deaf-blind participants were impaired in temporal discrimination as compared to controls, while deaf-blind individuals outperformed blind participants in the spatial tactile task. Overall, sensory-deprived participants did not show an enhanced tactile performance. We speculate that discriminative touch is not so relevant in humans, while social touch is. Probably, more complex tactile tasks would have revealed an increased performance in sensory-deprived people.

  9. Corneal blindness: a global perspective.

    PubMed Central

    Whitcher, J. P.; Srinivasan, M.; Upadhyay, M. P.

    2001-01-01

    Diseases affecting the cornea are a major cause of blindness worldwide, second only to cataract in overall importance. The epidemiology of corneal blindness is complicated and encompasses a wide variety of infectious and inflammatory eye diseses that cause corneal scarring, which ultimately leads to functional blindness. In addition, the prevalence of corneal disease varies from country to country and even from one population to another. While cataract is responsible for nearly 20 million of the 45 million blind people in the world, the next major cause is trachoma which blinds 4.9 million individuals, mainly as a result of corneal scarring and vascularization. Ocular trauma and corneal ulceration are significant causes of corneal blindness that are often underreported but may be responsible for 1.5-2.0 million new cases of monocular blindness every year. Causes of childhood blindness (about 1.5 million worldwide with 5 million visually disabled) include xerophthalmia (350,000 cases annually), ophthalmia neonatorum, and less frequently seen ocular diseases such as herpes simplex virus infections and vernal keratoconjunctivitis. Even though the control of onchocerciasis and leprosy are public health success stories, these diseases are still significant causes of blindness--affecting a quarter of a million individuals each. Traditional eye medicines have also been implicated as a major risk factor in the current epidemic of corneal ulceration in developing countries. Because of the difficulty of treating corneal blindness once it has occurred, public health prevention programmes are the most cost-effective means of decreasing the global burden of corneal blindness. PMID:11285665

  10. Overview on Deaf-Blindness

    ERIC Educational Resources Information Center

    Miles, Barbara

    2008-01-01

    It may seem that deaf-blindness refers to a total inability to see or hear. However, in reality deaf-blindness is a condition in which the combination of hearing and visual losses in children cause "such severe communication and other develop mental and educational needs that they cannot be accommodated in special education programs solely for…

  11. Biological Models for Blind Students.

    ERIC Educational Resources Information Center

    Franks, Frank L.; Murr, Marvin J.

    1978-01-01

    In response to an expressed need for inexpensive biological models for blind students, the American Printing House for the Blind has developed a set of 19 plastic models (schematics), which illustrate representative species of the major invertebrate phyla and component structures of flowering plants. (Author)

  12. Biological Models for Blind Students.

    ERIC Educational Resources Information Center

    Franks, Frank L.; Murr, Marvin J.

    1978-01-01

    In response to an expressed need for inexpensive biological models for blind students, the American Printing House for the Blind has developed a set of 19 plastic models (schematics), which illustrate representative species of the major invertebrate phyla and component structures of flowering plants. (Author)

  13. Conceptualizing the Gifted Blind Child.

    ERIC Educational Resources Information Center

    Chorniak, Evelyn J.

    A program director at an Ontario school for the blind discusses the phenomenon of giftedness in blind students. A section on identification addresses factors involved in IQ measurement, language, creative and productive thinking, high capacity for seeing diverse relationships, goal oriented behavior, sensitivity to expectations and feelings of…

  14. Load Induced Blindness

    PubMed Central

    Macdonald, James S. P.; Lavie, Nilli

    2008-01-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005d`) was consistently reduced with high, compared to low, perceptual load but was unaffected by the level of working memory load. Because alternative accounts in terms of expectation, memory, response bias, and goal-neglect due to the more strenuous high load task were ruled out, these experiments clearly demonstrate that high perceptual load determines conscious perception, impairing the ability to merely detect the presence of a stimulus—a phenomenon of load induced blindness. PMID:18823196

  15. Blindness from quinine toxicity.

    PubMed Central

    Bacon, P; Spalton, D J; Smith, S E

    1988-01-01

    We report a case of quinine overdose in a 47-year-old man who presented with blindness. Fundus photography demonstrates the acute and subsequent retinal changes, and his visual recovery to normal acuity with visual field constriction is documented. Pupillary and electrodiagnostic findings are recorded. Stellate ganglion block has been widely advocated as a helpful therapeutic measure, but out patient was treated with a unilateral stellate ganglion block without apparent benefit to that eye. From a review of the literature we believe that quinine produces its effects by toxicity on the retina rather than by vasoconstriction and that stellate ganglion block probably does not alter the natural history of the retinal toxicity. Images PMID:3281709

  16. Blind Pilot Decontamination

    NASA Astrophysics Data System (ADS)

    Muller, Ralf R.; Cottatellucci, Laura; Vehkapera, Mikko

    2014-10-01

    A subspace projection to improve channel estimation in massive multi-antenna systems is proposed and analyzed. Together with power-controlled hand-off, it can mitigate the pilot contamination problem without the need for coordination among cells. The proposed method is blind in the sense that it does not require pilot data to find the appropriate subspace. It is based on the theory of large random matrices that predicts that the eigenvalue spectra of large sample covariance matrices can asymptotically decompose into disjoint bulks as the matrix size grows large. Random matrix and free probability theory are utilized to predict under which system parameters such a bulk decomposition takes place. Simulation results are provided to confirm that the proposed method outperforms conventional linear channel estimation if bulk separation occurs.

  17. How to Succeed at Being Blind

    ERIC Educational Resources Information Center

    Selvin, Hanan C.

    1976-01-01

    The author, a professional sociologist who lost his sight, provides practical advice and information to people who are becoming blind or who have recently become blind, and others who know or work with blind persons. (Author/IM)

  18. Causes of Blindness in Canada

    PubMed Central

    MacDonald, Alexander E.

    1965-01-01

    A survey of blind persons in Canada, based on registrations with The Canadian National Institute for the Blind (C.N.I.B.), is reported. This is the first study of its type having national scope and based on data registered in a central file. It covered 24,605 living registered blind persons ranging from premature infants to very elderly persons. Causes of blindness are broken down with respect to topography (site and type of lesion) and etiology. In terms of frequency, the principal causes were lesions affecting the globe (e.g. glaucoma, myopia), 36%; the retina, 23%; the lens, 16%; and the optic nerve, 11%. In this study, 32% of the blindness was due to prenatal causes. The prevalence of blindness per 100,000 persons in Canada, based on C.N.I.B. data, was 131, varying among the provinces from 108 to 376. Serious ocular disease was four times more prevalent than blindness; 101,436 such cases (the prevention group) were listed by the C.N.I.B. PMID:14270210

  19. Drug user treatment failure blindness?

    PubMed

    Einstein, Stan

    2012-01-01

    An ethnographic case study of a "failed" single goal (abstinence) based individual and group therapy treatment of a New York City, Harlem-based, single, young-adult of color, IDU, mother, which ended in "death by overdose," after a period of abstinence, is presented almost 50 years later, in which complex, multidimensional structural barriers, "normed," consensualized, ideologically-driven preconceptions and an array of contextual, situational and relevant stakeholder factors, which may have resulted in intervention "failure blindness," are reviewed. The need to introduce failure analysis, blindness and management, as well as success analysis, blindness and management, as integral parts of treatment planning, implementation and assessment is raised.

  20. Perceptual Repetition Blindness Effects

    NASA Technical Reports Server (NTRS)

    Hochhaus, Larry; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    The phenomenon of repetition blindness (RB) may reveal a new limitation on human perceptual processing. Recently, however, researchers have attributed RB to post-perceptual processes such as memory retrieval and/or reporting biases. The standard rapid serial visual presentation (RSVP) paradigm used in most RB studies is, indeed, open to such objections. Here we investigate RB using a "single-frame" paradigm introduced by Johnston and Hale (1984) in which memory demands are minimal. Subjects made only a single judgement about whether one masked target word was the same or different than a post-target probe. Confidence ratings permitted use of signal detection methods to assess sensitivity and bias effects. In the critical condition for RB a precue of the post-target word was provided prior to the target stimulus (identity precue), so that the required judgement amounted to whether the target did or did not repeat the precue word. In control treatments, the precue was either an unrelated word or a dummy.

  1. Orthographic repetition blindness.

    PubMed

    Harris, C L; Morris, A L

    2000-11-01

    Repetition blindness (RB) is the failure to report the second occurrence of a repeated word, when words are sequentially and briefly displayed (Kanwisher, 1987). RB is also observed for non-identical words, such as home, dome. Explanations for non-identity RB assume that similarity at the level of the whole word causes the second word to be suppressed ("similarity inhibition"). Three experiments demonstrate that RB is robust for diverse types of orthographic relatedness, including critical words that share only their first initial letter, their last two letters, first three letters, middle three letters, beginning and final letters, three alternating letters, and three non-aligned letters (as in chance hand). The theoretical construct of similarity inhibition may be able to account for these data, although one mechanism previously proposed in the literature, neighbourhood inhibition, is probably not a useful way to explain the data on RB for words sharing only one or two letters. We introduce an alternative explanation for orthographic RB: Only the repeated letters are suppressed, and amount of RB depends on how easily the perceiver can reconstruct the target word from the non-suppressed letters.

  2. Reusable captive blind fastener

    NASA Technical Reports Server (NTRS)

    Peterson, S. A. (Inventor)

    1981-01-01

    A one piece reusable fastener capable of joining materials together from one side (blind backside) comprises a screw driven pin ending in a wedge-shaped expander cone. The cone cooperates within a slotted collar end which has a number of tangs on a cylindrical body. The fastener is set by inserting it through aligned holes in the workpieces to be joined. Turning the pin in one direction draws the cone into the collar, deforming the tangs radially outward to mate with tapered back-tapered hold in the workpiece, thus fastening the two pieces together. Reversing the direction of the pin withdraws the cone from the collar, and allows the tangs to resume their contracted configuration without withdrawing the fastener from the insertion hole. The fastener is capable of joining materials together from only one side with substantial strength in tension and shear over many resue attachment cycles, with no special operations on the main assembly parts other than the tapering of the back end of the insertion hole.

  3. Load induced blindness.

    PubMed

    Macdonald, James S P; Lavie, Nilli

    2008-10-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005, for a review). Here we varied the level of perceptual load in a letter-search task and assessed its effect on the conscious perception of a search-irrelevant shape stimulus appearing in the periphery, using a direct measure of awareness (present/absent reports). Detection sensitivity (d') was consistently reduced with high, compared to low, perceptual load but was unaffected by the level of working memory load. Because alternative accounts in terms of expectation, memory, response bias, and goal-neglect due to the more strenuous high load task were ruled out, these experiments clearly demonstrate that high perceptual load determines conscious perception, impairing the ability to merely detect the presence of a stimulus--a phenomenon of load induced blindness.

  4. Perceptual repetition blindness effects.

    PubMed

    Hochhaus, L; Johnston, J C

    1996-04-01

    Repetition blindness (RB) may reveal a new limitation on human perceptual processing. Recently, however, researchers have attributed RB to postperceptual processes. The standard rapid serial visual presentation (RSVP) paradigm used in most RB studies is open to such objections. The "single-frame" paradigm introduced by J. C. Johnston and B. L. Hale (1984) allowed investigation of RB with minimal memory demands. Participants made a judgment about whether 1 masked target word was the same or different than a posttarget probe. Confidence ratings permitted use of signal detection methods. In the critical condition for RB, a precue of the posttarget word was provided prior to the target stimulus so that the required judgment amounted to whether the target did or did not repeat the precue word. In control treatments, the precue was an unrelated word or a dummy. Results showed that perceptual sensitivity was significantly reduced in the RB condition relative to baseline control conditions. The data showed that RB can be obtained under conditions in which memory problems are minimal and perceptual sensitivity is assessed independently of biases. RB therefore can be a perceptual phenomenon.

  5. Analysis of the morphology and distribution of argentaffin, argyrophil and insulin-immunoreactive endocrine cells in the small intestine of the adult opossum Didelphis aurita (Wied-Neuwied, 1826).

    PubMed

    Basile, D R S; Novaes, R D; Marques, D C S; Fialho, M C Q; Neves, C A; Fonseca, C C

    2012-10-01

    The aim of this study was to identify and quantify the argyrophil, argentaffin and insulin-immunoreactive cells (IIC) in the small intestine of the opossum Didelphis aurita. Seven adult male specimens of opossums were investigated. The animals were captured, and their blood insulin levels were determined. After euthanasia, fragments of the small intestine were processed for light microscopy and transmission electron microscopy, and submitted to histochemistry and immunohistochemistry for identification of argyrophil and argentaffin endocrine cells, and IIC. Argyrophil and argentaffin cells were identified in the intestinal villi and Liberkühn crypts, whereas IIC were present exclusively in the crypts. Ultrastructure of the IIC revealed cytoplasmic granules of different sizes and electron densities. The numbers of IIC per mm(2) in the duodenum and jejunum were higher than in the ileum (p<0.05). The animals had low levels of blood insulin (2.8 ± 0.78 μIU/ml). There was no correlation between insulin levels and the number of IIC in the small intestine. The IIC presented secretory granules, elongated and variable morphology. It is believed that insulin secretion by the IIC may influence the proliferation of cells in the Liberkühn crypts, and local glucose homeostasis, primarily in animals with low serum insulin levels, such as the opossum. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Attentional inhibition mediates inattentional blindness.

    PubMed

    Thakral, Preston P; Slotnick, Scott D

    2010-06-01

    Salient stimuli presented at unattended locations are not always perceived, a phenomenon termed inattentional blindness. We hypothesized that inattentional blindness may be mediated by attentional inhibition. It has been shown that attentional inhibition effects are maximal near an attended location. If our hypothesis is correct, inattentional blindness effects should similarly be maximal near an attended location. During central fixation, participants viewed rapidly presented colored digits at a peripheral location. An unexpected black circle (the critical stimulus) was concurrently presented. Participants were instructed to maintain central fixation and name each color/digit, requiring focused attention to that location. For each participant, the critical stimulus was presented either near to or far from the attended location (at the same eccentricity). In support of our hypothesis, inattentional blindness effects were maximal near the attended location, but only at intermediate task accuracy. 2010 Elsevier Inc. All rights reserved.

  7. Laboratory Techniques for the Blind

    ERIC Educational Resources Information Center

    Tombaugh, Dorothy

    1972-01-01

    Describes modifications of laboratory procedures for the BSCS Green Version biology, including dissection, microbiology, animal behavior, physiology, biochemistry, and genetics that make the methods suitable for direct experimentation by blind students. Discusses models as substitutes for microscopy. (AL)

  8. Vision following extended congenital blindness.

    PubMed

    Ostrovsky, Yuri; Andalman, Aaron; Sinha, Pawan

    2006-12-01

    Animal studies suggest that early visual deprivation can cause permanent functional blindness. However, few human data on this issue exist. Given enough time for recovery, can a person gain visual skills after several years of congenital blindness? In India, we recently had an unusual opportunity to work with an individual whose case history sheds light on this question. S.R.D. was born blind, and remained so until age 12. She then underwent surgery for the removal of dense congenital cataracts. We evaluated her performance on an extensive battery of visual tasks 20 years after surgery. We found that although S.R.D.'s acuity is compromised, she is proficient on mid- and high-level visual tasks. These results suggest that the human brain retains an impressive capacity for visual learning well into late childhood. They have implications for current conceptions of cortical plasticity and provide an argument for treating congenital blindness even in older children.

  9. American Foundation for the Blind

    MedlinePlus

    ... more and purchase tickets or sponsorships. Dealing with Crime or Domestic Violence VisionAware has compiled resources to ... people who are blind or visually impaired prevent crime, protect themselves, and know what to do in ...

  10. Laboratory Techniques for the Blind

    ERIC Educational Resources Information Center

    Tombaugh, Dorothy

    1972-01-01

    Describes modifications of laboratory procedures for the BSCS Green Version biology, including dissection, microbiology, animal behavior, physiology, biochemistry, and genetics that make the methods suitable for direct experimentation by blind students. Discusses models as substitutes for microscopy. (AL)

  11. Student Art for Blind Children.

    ERIC Educational Resources Information Center

    Vanda, Kay

    1982-01-01

    Describes a project in which high school student volunteers designed art activities for blind children. Students incorporated the sensation of motion and texture into their designs for toys, puzzles, games, and story illustrations. (AM)

  12. A Perceptual Repetition Blindness Effect

    NASA Technical Reports Server (NTRS)

    Hochhaus, Larry; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    Before concluding Repetition Blindness is a perceptual phenomenon, alternative explanations based on memory retrieval problems and report bias must be rejected. Memory problems were minimized by requiring a judgment about only a single briefly displayed field. Bias and sensitivity effects were empirically measured with an ROC-curve analysis method based on confidence ratings. Results from five experiments support the hypothesis that Repetition Blindness can be a perceptual phenomenon.

  13. [The blind and autogenic training].

    PubMed

    Carrozzini, R L; Primo Carrozzini, M M

    1983-09-29

    The orthodox application of J. H. Schultz's A.T. technique for bringing about change, growth and maturity in the blind and in this way helping them to face their existence more serenely is briefly described. The case of Miss. Anna D. clearly shows how Schultz's technique gave a blind person the possibility from the age of 2 of "seeing" colours, shades and images and also to dream in colour.

  14. Simple pendulum for blind students

    NASA Astrophysics Data System (ADS)

    Goncalves, A. M. B.; Cena, C. R.; Alves, D. C. B.; Errobidart, N. C. G.; Jardim, M. I. A.; Queiros, W. P.

    2017-09-01

    Faced with the need to teach physics to the visually impaired, in this paper we propose a way to demonstrate the dependence of distance and time in a pendulum experiment to blind students. The periodic oscillation of the pendulum is translated, by an Arduino and an ultrasonic sensor, in a periodic variation of frequency in a speaker. The main advantage of this proposal is the possibility that a blind student understands the movement without necessity of touching it.

  15. What It's Like to Be Color Blind

    MedlinePlus

    ... A Real Lifesaver Kids Talk About: Coaches What It's Like to Be Color Blind KidsHealth > For Kids > What It's Like to Be Color Blind Print A A ... blind. But some people really are color blind. It doesn't mean they can't see any ...

  16. Programs for the Deaf-Blind.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1991

    1991-01-01

    This directory lists contact information for programs for the deaf-blind in the United States in 3 categories: (1) programs for deaf-blind children and youth (29 programs listed); (2) Helen Keller National Center for Deaf-Blind Youth and Adults (1 national and 10 regional offices); and (3) programs for training teachers of the deaf-blind (4…

  17. ESTIMATED STATISTICS ON BLINDNESS AND VISION PROBLEMS. NATIONAL SOCIETY FOR THE PREVENTION OF BLINDNESS FACT BOOK.

    ERIC Educational Resources Information Center

    HATFIELD, ELIZABETH M.

    CURRENT ESTIMATES AND SOME TREND DATA ARE PRESENTED ON THE FOLLOWING SUBJECTS -- POPULATION GROWTH (1940-1960), PREVALENCE OF LEGAL BLINDNESS, NEW CASES OF LEGAL BLINDNESS, AGE DISTRIBUTION OF LEGALLY BLIND PERSONS, CAUSES OF LEGAL BLINDNESS, CHANGING PATTERNS IN CAUSES OF LEGAL BLINDNESS, CASES OF GLAUCOMA, SCHOOL CHILDREN NEEDING EYE CARE,…

  18. ESTIMATED STATISTICS ON BLINDNESS AND VISION PROBLEMS. NATIONAL SOCIETY FOR THE PREVENTION OF BLINDNESS FACT BOOK.

    ERIC Educational Resources Information Center

    HATFIELD, ELIZABETH M.

    CURRENT ESTIMATES AND SOME TREND DATA ARE PRESENTED ON THE FOLLOWING SUBJECTS -- POPULATION GROWTH (1940-1960), PREVALENCE OF LEGAL BLINDNESS, NEW CASES OF LEGAL BLINDNESS, AGE DISTRIBUTION OF LEGALLY BLIND PERSONS, CAUSES OF LEGAL BLINDNESS, CHANGING PATTERNS IN CAUSES OF LEGAL BLINDNESS, CASES OF GLAUCOMA, SCHOOL CHILDREN NEEDING EYE CARE,…

  19. [Aiming for zero blindness].

    PubMed

    Nakazawa, Toru

    2015-03-01

    Glaucoma is the leading cause of acquired blindness in Japan. One reason that it often leads to blindness is that it can continue to worsen even after effective medical reduction of intraocular pressure (IOP), the only evidence-based treatment. The limitations of current treatments make it critical to identify IOP-independent factors that can cause glaucoma and develop new drugs to target these factors. This is a challenging task, as the pathology of glaucoma is thought to be very complex, with different combinations of factors underlying its development and progression in different patients. Additionally, there is a deficiency in methods to efficiently perform clinical evaluations and reliably probe the state of the disease over relatively short periods. In addition, newly developed drugs need to be evaluated with clinical trials, for which human and financial resources are limited, before they can be widely used for treatment. Taking all these issues into consideration, it is evident that there are two urgent issues to consider: the development of methods to classify glaucoma in detail based on its pathology, and the improvement of clinical evaluation methods. In this review, we discuss some of our efforts to develop new neuroprotective agents for glaucoma, with a focus on the following three areas: 1. Clinical research and development of methods to classify glaucoma in detail based on IOP-independent factors, and the exploration of possibilities for the improvement of clinical evaluation of glaucoma. 2. Pathology-based research and development of new drugs for glaucoma, focusing on comprehensive gene expression analysis and the development of molecule-targeting drugs, using murine optic nerve crush as a disease model. 3. Development of next generation in vivo imaging modalities and the establishment of infrastructure enabling "big-data" analysis. First, we discuss our clinical research and the development of methods to classify glaucoma in detail based on IOP

  20. 20 CFR 416.982 - Blindness under a State plan.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Blindness under a State plan. 416.982 Section..., BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.982 Blindness under a State... plan because of your blindness for the month of December 1973; and (c) You continue to be blind as...

  1. 20 CFR 416.983 - How we evaluate statutory blindness.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false How we evaluate statutory blindness. 416.983... AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.983 How we evaluate statutory blindness. We will find that you are blind if you are statutorily blind within the meaning of...

  2. 20 CFR 416.982 - Blindness under a State plan.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Blindness under a State plan. 416.982 Section..., BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.982 Blindness under a State... plan because of your blindness for the month of December 1973; and (c) You continue to be blind as...

  3. 20 CFR 416.983 - How we evaluate statutory blindness.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false How we evaluate statutory blindness. 416.983... AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.983 How we evaluate statutory blindness. We will find that you are blind if you are statutorily blind within the meaning of...

  4. 20 CFR 416.983 - How we evaluate statutory blindness.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false How we evaluate statutory blindness. 416.983... AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.983 How we evaluate statutory blindness. We will find that you are blind if you are statutorily blind within the meaning of...

  5. 20 CFR 416.982 - Blindness under a State plan.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Blindness under a State plan. 416.982 Section..., BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.982 Blindness under a State... plan because of your blindness for the month of December 1973; and (c) You continue to be blind as...

  6. 20 CFR 416.983 - How we evaluate statutory blindness.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false How we evaluate statutory blindness. 416.983... AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.983 How we evaluate statutory blindness. We will find that you are blind if you are statutorily blind within the meaning of...

  7. 20 CFR 416.982 - Blindness under a State plan.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Blindness under a State plan. 416.982 Section..., BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.982 Blindness under a State... plan because of your blindness for the month of December 1973; and (c) You continue to be blind as...

  8. 20 CFR 416.982 - Blindness under a State plan.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Blindness under a State plan. 416.982 Section..., BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.982 Blindness under a State... plan because of your blindness for the month of December 1973; and (c) You continue to be blind as...

  9. 20 CFR 416.983 - How we evaluate statutory blindness.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false How we evaluate statutory blindness. 416.983... AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.983 How we evaluate statutory blindness. We will find that you are blind if you are statutorily blind within the meaning of...

  10. Do the blinds smell better?

    PubMed

    Luers, Jan Christoffer; Mikolajczak, Stefanie; Hahn, Moritz; Wittekindt, Claus; Beutner, Dirk; Hüttenbrink, Karl-Bernd; Damm, Michael

    2014-07-01

    If people lose a sense organ, there is thought to be an increase in the remaining sensory functions. Previous studies showed ambiguous results on this topic. In a prospective matched pair case-control study on 46 blind and 46 normal-sighted subjects, the olfactory performance was examined using the Sniffin' Sticks Test [threshold-discrimination-identification (TDI) test], determining the olfactory threshold, the identification and the discrimination performance. There was no significant difference between the groups. Neither the overall olfactory performance (TDI score) nor any of its subtests did correlate with the vision or with the duration of blindness. The study could not detect any superior smell abilities of blind subjects as compared to sighted subjects.

  11. Epidemiology of blindness in children.

    PubMed

    Solebo, Ameenat Lola; Teoh, Lucinda; Rahi, Jugnoo

    2017-09-01

    An estimated 14 million of the world's children are blind. A blind child is more likely to live in socioeconomic deprivation, to be more frequently hospitalised during childhood and to die in childhood than a child not living with blindness. This update of a previous review on childhood visual impairment focuses on emerging therapies for children with severe visual disability (severe visual impairment and blindness or SVI/BL).For children in higher income countries, cerebral visual impairment and optic nerve anomalies remain the most common causes of SVI/BL, while retinopathy of prematurity (ROP) and cataract are now the most common avoidable causes. The constellation of causes of childhood blindness in lower income settings is shifting from infective and nutritional corneal opacities and congenital anomalies to more resemble the patterns seen in higher income settings. Improvements in maternal and neonatal health and investment in and maintenance of national ophthalmic care infrastructure are the key to reducing the burden of avoidable blindness. New therapeutic targets are emerging for childhood visual disorders, although the safety and efficacy of novel therapies for diseases such as ROP or retinal dystrophies are not yet clear. Population-based epidemiological research, particularly on cerebral visual impairment and optic nerve hypoplasia, is needed in order to improve understanding of risk factors and to inform and support the development of novel therapies for disorders currently considered 'untreatable'. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Experimental infection of the opossum Didelphis aurita by Rickettsia felis, Rickettsia bellii, and Rickettsia parkeri and evaluation of the transmission of the infection to ticks Amblyomma cajennense and Amblyomma dubitatum.

    PubMed

    Horta, Maurício C; Sabatini, Guilherme S; Moraes-Filho, Jonas; Ogrzewalska, Maria; Canal, Raoní B; Pacheco, Richard C; Martins, Thiago F; Matushima, Eliana R; Labruna, Marcelo B

    2010-12-01

    This work evaluated the infection of opossums (Didelphis aurita) by Rickettsia felis, Rickettsia bellii, and Rickettsia parkeri and their role as amplifier hosts for horizontal transmission to Amblyomma cajennense and/or Amblyomma dubitatum ticks. Infection in D. aurita was induced by intraperitoneal inoculation with R. felis (n = 4 opossums), R. bellii (n = 4), and R. parkeri (n = 2). Another group of six opossums were inoculated intraperitoneally with Leibovitz-15 sterile culture medium, representing the uninfected groups (n = 2 opossums simultaneously to each infected group). Opossum blood samples collected during the study were used for DNA extraction, followed by real-time polymerase chain reaction targeting the rickettsial gene gltA, hematology, and detection of Rickettsia spp.-reactive antibodies by indirect immunofluorescence assay. Opossums were infested with uninfected A. cajennense and/or A. dubitatum for 30 days postinoculation (DPI). Flat ticks molted from ticks fed on opossums were allowed to feed on uninfected rabbits, which were tested for seroconversion by immunofluorescence assay. Samples of flat ticks were also tested by real-time polymerase chain reaction. Inoculated opossums showed no clinical abnormalities. Antibodies to Rickettsia spp. were first detected at the second to fourth DPI, with detectable titers until the 150th DPI. Rickettsemia was detected only in one opossum inoculated with R. parkeri, at the eighth DPI. Only one A. cajennense tick (2.0%) previously fed on a R. parkeri-inoculated opossum became infected. None of the rabbits infested with opossum-derived ticks seroconverted. The study demonstrated that R. felis, R. bellii, and R. parkeri were capable to produce antibody response in opossums, however, with undetectable rickettsemia for R. felis and R. bellii, and very low rickettsemia for R. parkeri. Further studies must be done with different strains of these rickettsiae, most importantly the strains that have

  13. Computer Reader for the Blind

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Optacon II uses the same basic technique of converting printed information into a tactile image as did Optacon. Optacon II can also be connected directly to a personal computer, which opens up a new range of job opportunities for the blind. Optacon II is not limited to reading printed words, it can convert any graphic image viewed by the camera. Optacon II demands extensive training for blind operators. TSI provides 60-hour training courses at its Mountain View headquarters and at training centers around the world. TeleSensory discontinued production of the Optacon as of December 1996.

  14. Night Blindness and Ancient Remedy

    PubMed Central

    Al Binali, H.A. Hajar

    2014-01-01

    The aim of this article is to briefly review the history of night blindness and its treatment from ancient times until the present. The old Egyptians, the Babylonians, the Greeks and the Arabs used animal liver for treatment and successfully cured the disease. The author had the opportunity to observe the application of the old remedy to a patient. Now we know what the ancients did not know, that night blindness is caused by Vitamin A deficiency and the animal liver is the store house for Vitamin A. PMID:25774260

  15. Piagetian Reasoning and the Blind.

    ERIC Educational Resources Information Center

    Hatwell, Yvette

    Available for the first time in an English translation, the book reports the results of a series of studies undertaken in the early 1960s on the cognitive development of children with congenital blindness. Chapters one and two review the literaure on such topics as the concept of sensory compensation and the nature of tactual space and provide…

  16. Metro Navigation for the Blind

    ERIC Educational Resources Information Center

    Sanchez, Jaime; Saenz, Mauricio

    2010-01-01

    This study evaluates the impact of using the software program AudioMetro, a tool that supports the orientation and mobility of people who are blind in the Metro system of Santiago de Chile. A quasi-experimental study considering experimental and control groups and using the paired Student's t in a two sample test analysis (pretest-posttest) was…

  17. PHYSICAL EDUCATION FOR BLIND CHILDREN.

    ERIC Educational Resources Information Center

    BUELL, CHARLES E.

    A PRACTICAL RATHER THAN A THEORETICAL REFERENCE GUIDE, THE BOOK DISCUSSES THE NEED OF THE BLIND OR VISUALLY IMPAIRED CHILD FOR PHYSICAL EDUCATION. PAST AND PRESENT PROGRAMS IN PUBLIC AND RESIDENTIAL SCHOOLS, RECREATION AND LEISURE TIME ACTIVITIES (A GUIDE FOR PARENTS), SPORTS AND INTERSCHOLASTIC COMPETITION, ACTIVE GAMES, CONTESTS, RELAYS, AND…

  18. Vision 2020: moving beyond blindness.

    PubMed

    Lewallen, Susan; Lansingh, Van; Thulasiraj, R D

    2014-09-01

    Most industrialized countries and many emerging economies have chosen to define 'blindness' at a visual acuity above that which WHO uses. This reflects the increasing visual demands of modern society for tasks such as driving or using cell phones. Meeting these demands will require more highly skilled health workers using more sophisticated equipment than has generally been considered sufficient for primary eye care.

  19. Sensory Aids for the Blind.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Committee on Prosthetics Research and Development.

    The problems of providing sensory aids for the blind are presented and a report on the present status of aids discusses direct translation and recognition reading machines as well as mobility aids. Aspects of required research considered are the following: assessment of needs; vision, audition, taction, and multimodal communication; reading aids,…

  20. The Blind Learning Aptitude Test.

    ERIC Educational Resources Information Center

    Newland, T. Ernest

    A Blind Learning Aptitude Test (BLAT) was developed on the basis of sense of touch rather than on conventional experience, fine sensory discrimination, or verbal competency. From a pool of about 350 items, most of them used in testing intelligence in the sighted, a pool of 94 was selected and embossed after the manner of braille. A residual pool…

  1. Reading Machines for Blind People.

    ERIC Educational Resources Information Center

    Fender, Derek H.

    1983-01-01

    Ten stages of developing reading machines for blind people are analyzed: handling of text material; optics; electro-optics; pattern recognition; character recognition; storage; speech synthesizers; browsing and place finding; computer indexing; and other sources of input. Cost considerations of the final product are emphasized. (CL)

  2. Metro Navigation for the Blind

    ERIC Educational Resources Information Center

    Sanchez, Jaime; Saenz, Mauricio

    2010-01-01

    This study evaluates the impact of using the software program AudioMetro, a tool that supports the orientation and mobility of people who are blind in the Metro system of Santiago de Chile. A quasi-experimental study considering experimental and control groups and using the paired Student's t in a two sample test analysis (pretest-posttest) was…

  3. Aquatic Recreation for the Blind.

    ERIC Educational Resources Information Center

    Cordellos, Harry C.

    The sixth in a series of booklets on physical education and recreation for the handicapped describes aquatic activities for blind persons. Written by a partially sighted athlete, the document discusses swimming pool characteristics and special pools for the visually impaired. Qualities of swimming instructors are reviewed, and suggestions for…

  4. Future trends in global blindness

    PubMed Central

    Resnikoff, Serge; Keys, Tricia U

    2012-01-01

    The objective of this review is to discuss the available data on the prevalence and causes of global blindness, and some of the associated trends and limitations seen. A literature search was conducted using the terms “global AND blindness” and “global AND vision AND impairment”, resulting in seven appropriate articles for this review. Since 1990 the estimate of global prevalence of blindness has gradually decreased when considering the best corrected visual acuity definition: 0.71% in 1990, 0.59% in 2002, and 0.55% in 2010, corresponding to a 0.73% reduction per year over the 2002–2010 period. Significant limitations were found in the comparability between the global estimates in prevalence or causes of blindness or visual impairment. These limitations arise from various factors such as uncertainties about the true cause of the impairment, the use of different definitions and methods, and the absence of data from a number of geographical areas, leading to various extrapolation methods, which in turn seriously limit comparability. Seminal to this discussion on limitations in the comparability of studies and data, is that blindness has historically been defined using best corrected visual acuity. PMID:22944747

  5. Reading Machines for Blind People.

    ERIC Educational Resources Information Center

    Fender, Derek H.

    1983-01-01

    Ten stages of developing reading machines for blind people are analyzed: handling of text material; optics; electro-optics; pattern recognition; character recognition; storage; speech synthesizers; browsing and place finding; computer indexing; and other sources of input. Cost considerations of the final product are emphasized. (CL)

  6. Repetition Blindness for Rotated Objects

    ERIC Educational Resources Information Center

    Hayward, William G.; Zhou, Guomei; Man, Wai-Fung; Harris, Irina M.

    2010-01-01

    Repetition blindness (RB) is the finding that observers often miss the repetition of an item within a rapid stream of words or objects. Recent studies have shown that RB for objects is largely unaffected by variations in viewpoint between the repeated items. In 5 experiments, we tested RB under different axes of rotation, with different types of…

  7. Repetition Blindness Occurs in Nonwords

    ERIC Educational Resources Information Center

    Harris, Catherine L.; Morris, Alison L.

    2004-01-01

    Theorists have predicted that repetition blindness (RB) should be absent for nonwords because they do not activate preexisting mental types. The authors hypothesized that RB would be observed for nonwords because RB can occur at a sublexical level. Four experiments showed that RB is observed for word-nonword pairs (noon noof), orthographically…

  8. Causes of blindness in northern Nigeria.

    PubMed

    Kragha, I K

    1987-09-01

    An analysis of the causes of blindness in northern Nigeria was undertaken. The leading causes of blindness in order of frequency of occurrence were cataracts, glaucoma, corneal diseases, trachoma, and trauma.

  9. Indiana School for the Blind Visits Goddard

    NASA Image and Video Library

    This video shows highlights of the Indiana School for the Blind and Visually Impaired, and the Indian Creek Public High School visit to NASA's Goddard Space Flight Center in June 2011. Both blind a...

  10. Poverty and blindness in Africa.

    PubMed

    Naidoo, Kovin

    2007-11-01

    Africa carries a disproportionate responsibility in terms of blindness and visual impairment. With approximately 10 per cent of the world's population, Africa has 19 per cent of the world's blindness. It is no surprise that this reality also mirrors the situation in terms of the burden of world poverty. There is an increasing recognition of the need to highlight the link between poverty, development and health care. Blindness, disabling visual impairment and the overall lack of eye-care services are too often the result of social, economic and developmental challenges of the developing world. The state of eye care in Africa stands in alarming contrast to that in the rest of the world. Poor practitioner-to-patient ratios, absence of eye-care personnel, inadequate facilities, poor state funding and a lack of educational programs are the hallmarks of eye care in Africa, with preventable and treatable conditions being the leading cause of blindness. Eye diseases causing preventable blindness are often the result of a combination of factors such as poverty, lack of education and inadequate health-care services. The challenge that Vision 2020 has set itself in Africa is enormous. Africa is not a homogenous entity, the inter- and intra-country differences in economic development, prevalence of disease, delivery infrastructure and human resources amplify the challenges of meeting eye-care needs. The successful implementation of Vision 2020 programs will be hindered without the development of a comprehensive, co-ordinated strategy that is cognisant of the differences that exist and the need for comprehensive solutions that are rooted in the economic and political realities of the continent as well as the individual countries and regions within countries. This strategy should recognise the need for economic growth that results in greater state funded eye-care services that focus on health promotion to ensure the prevention of eye disease, the development of eye clinics in

  11. Partially Blind Signatures Based on Quantum Cryptography

    NASA Astrophysics Data System (ADS)

    Cai, Xiao-Qiu; Niu, Hui-Fang

    2012-12-01

    In a partially blind signature scheme, the signer explicitly includes pre-agreed common information in the blind signature, which can improve the availability and performance. We present a new partially blind signature scheme based on fundamental properties of quantum mechanics. In addition, we analyze the security of this scheme, and show it is not possible to forge valid partially blind signatures. Moreover, the comparisons between this scheme and those based on public-key cryptography are also discussed.

  12. "VisionTouch Phone" for the Blind.

    PubMed

    Yong, Robest

    2013-10-01

    Our objective is to enable the blind to use smartphones with touchscreens to make calls and to send text messages (sms) with ease, speed, and accuracy. We believe that with our proposed platform, which enables the blind to locate the position of the keypads, new games and education, and safety applications will be increasingly developed for the blind. This innovative idea can also be implemented on tablets for the blind, allowing them to use information websites such as Wikipedia and newspaper portals.

  13. 45 CFR 233.70 - Blindness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false Blindness. 233.70 Section 233.70 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.70 Blindness. (a) State plan requirements. A State plan under title X or XVI of the Social Security Act must: (1) Contain a definition of blindness in terms of ophthalmic...

  14. 45 CFR 233.70 - Blindness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Blindness. 233.70 Section 233.70 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.70 Blindness. (a) State plan requirements. A State plan under title X or XVI of the Social Security Act must: (1) Contain a definition of blindness in terms of ophthalmic...

  15. 45 CFR 233.70 - Blindness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Blindness. 233.70 Section 233.70 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.70 Blindness. (a) State plan requirements. A State plan under title X or XVI of the Social Security Act must: (1) Contain a definition of blindness in terms of ophthalmic...

  16. 45 CFR 233.70 - Blindness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 2 2014-10-01 2012-10-01 true Blindness. 233.70 Section 233.70 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.70 Blindness. (a) State plan requirements. A State plan under title X or XVI of the Social Security Act must: (1) Contain a definition of blindness in terms of ophthalmic...

  17. 45 CFR 233.70 - Blindness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true Blindness. 233.70 Section 233.70 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.70 Blindness. (a) State plan requirements. A State plan under title X or XVI of the Social Security Act must: (1) Contain a definition of blindness in terms of ophthalmic...

  18. Psychomotor Development for the Deaf-Blind.

    ERIC Educational Resources Information Center

    Sherrill, Claudine

    The stages of psychomotor development in deaf blind children and youth are reviewed, and educational principles to guide psychomotor development programs for the deaf blind are outlined. Etiological factors which contribute to the psychomotor development of deaf blind persons are discussed including nonambulation and sensory deprivation, heart…

  19. Introduction to Deaf-Blindness Workshop.

    ERIC Educational Resources Information Center

    Rhodes, Larry

    This document presents the agenda and materials distributed at a 1-day introductory workshop on deaf-blindness. Introductory material explains the workshop's purpose and rules. A short test contrasts facts and myths about deaf-blindness. A handout presents information on the dynamics of deaf-blindness, etiologies in the adult deaf-blind…

  20. What It's Like to Be Color Blind

    MedlinePlus

    ... a green leaf might look tan or gray. Color Blindness Is Passed Down Color blindness is almost always an inherited (say: in-HER- ... Eye doctors (and some school nurses) test for color blindness by showing a picture made up of different ...

  1. Deaf-Blind Perspectives, 1997-1998.

    ERIC Educational Resources Information Center

    Deaf-Blind Perspectives, 1998

    1998-01-01

    This one-year collection of three serial issues focuses on problem solving skills for children with deaf-blindness, the history and change in the education of children who are deaf-blind since the rubella epidemic of the 1960's, and early identification of infants who are deaf-blind. Specific articles include: (1) "Research to Practice Focus…

  2. Deaf-Blind Perspectives, 1998-1999.

    ERIC Educational Resources Information Center

    Malloy, Peggy, Ed.

    1998-01-01

    This collection of three issues focuses on competencies for teachers of learners who are deaf-blind, living with deaf-blindness, and resources in Australia for parents and families of students who are deaf-blind. Articles include: (1) "Research-to-Practice Focus: Competencies for Teachers of Learners Who Are Deafblind" (Marianne Riggio),…

  3. Congenital Blindness Leads to Enhanced Vibrotactile Perception

    ERIC Educational Resources Information Center

    Wan, Catherine Y.; Wood, Amanda G.; Reutens, David C.; Wilson, Sarah J.

    2010-01-01

    Previous studies have shown that in comparison with the sighted, blind individuals display superior non-visual perceptual abilities and differ in brain organisation. In this study, we investigated the performance of blind and sighted participants on a vibrotactile discrimination task. Thirty-three blind participants were classified into one of…

  4. Programs for the Deaf-Blind.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1990

    1990-01-01

    The directory lists 28 state or multistate programs for deaf blind children and youth, the national center and 10 regional offices of the Helen Keller National Center for Deaf-Blind Youths and Adults, and 4 programs for training teachers of the deaf-blind. Information usually provided includes, address, director's name, and phone number. (DB)

  5. Model Deaf/Blind Prevocational Training Project.

    ERIC Educational Resources Information Center

    Stoddard, Denis W.; And Others

    Presented is a report of a 4-month project designed to review literature on projects pertaining to deaf-blind prevocational training, to implement a model prevocational program for six severely handicapped deaf-blind students (10 years old), and to conduct two workshops in the area of prevocational training for deaf-blind students. Provided in…

  6. Blindness, cataract surgery and mortality in Ethiopia.

    PubMed

    Thomas, Benjamin J; Sanders, David S; Oliva, Matthew S; Orrs, Mark S; Glick, Peter; Ruit, Sanduk; Chen, Wei; Luoto, Jill; Tasfaw, Alemu Kerie; Tabin, Geoffrey C

    2016-09-01

    To examine the relationships between blindness, the intervention of cataract surgery and all-cause mortality in a rural Ethiopian population. Population-based, interventional prospective study. Community-based detection methods identified blind Ethiopian persons from two selected kebeles in Amhara region, Ethiopia. Data from 1201 blind patients were collected-628 cataract-blind and 573 blind from other conditions. Free cataract surgery was provided for consenting, cataract-blind patients. Follow-up surveys were conducted after 12 months (±1 month)-the main outcome measure for this report is all-cause mortality at 1 year. During the follow-up period, 110 persons died from the selected population (mortality 9.2%), which consisted of those cataract-blind patients who received cataract surgery (N=461), cataract-blind patients who did not receive surgery (N=167) and all non-cataract-blind patients (N=573). Of the 461 patients who received cataract surgery, 44 patients died (9.5%). Of the 740 patients who did not receive surgery, 66 died (8.9%)-28 patients from the cohort of cataract-blind patients who did not receive surgery (16.8%) and 38 patients from the cohort of non-cataract blind (6.6%). Subgroup analysis revealed significantly increased odds of mortality for cataract-blind patients over 75 years of age who did not receive surgery and for unmarried patients of all age groups. In this population, mortality risk was significantly elevated for older cataract-blind patients when compared with non-cataract-blind patients-an elevation of risk that was not noted in an age-matched cohort of cataract-blind patients who underwent cataract surgery as early as 1-year follow-up. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Color blindness and Rorschach color responsivity.

    PubMed

    Corsino, B V

    1985-10-01

    Color vision deficits occur in 10% of the American white male population. Thus, color blindness may invalidate diagnostic hypotheses generated from Rorschach data. The Rorschach protocols of 43 white, college male color-blind subjects were compared to the protocols of normally sighted controls. The color-blind group manifested fewer pure "C" responses. No significant between group differences emerged for any of the other primary Rorschach color variables. Pure "C" responses rarely figure prominently in Rorschach evaluations, and the apparent lowered frequency of these responses by the color-blind is insufficient to warrant modification of current Rorschach practice. The data suggest that color blindness is unlikely to confound Rorschach assessment.

  8. Mobility aid for the blind

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A project to develop an effective mobility aid for blind pedestrians which acquires consecutive images of the scenes before a moving pedestrian, which locates and identifies the pedestrian's path and potential obstacles in the path, which presents path and obstacle information to the pedestrian, and which operates in real-time is discussed. The mobility aid has three principal components: an image acquisition system, an image interpretation system, and an information presentation system. The image acquisition system consists of a miniature, solid-state TV camera which transforms the scene before the blind pedestrian into an image which can be received by the image interpretation system. The image interpretation system is implemented on a microprocessor which has been programmed to execute real-time feature extraction and scene analysis algorithms for locating and identifying the pedestrian's path and potential obstacles. Identity and location information is presented to the pedestrian by means of tactile coding and machine-generated speech.

  9. Change blindness and eyewitness testimony.

    PubMed

    Davies, Graham; Hine, Sarah

    2007-07-01

    The authors explored the relevance of research on change blindness to eyewitness identification and testimony under intentional and incidental memory conditions. Participants (N = 80, 40 men and 40 women) viewed a video enactment of a burglary in which the identity of the burglar changed at the halfway point of the film. Half of participants were briefed to remember the content, and the other half were not. All were tested for the recall of the content, awareness of the change, and ability to identify either or both of the burglars. Some 61% of participants did not notice the identity change. Rates of detection were significantly higher in participants in the intentional condition, who also recalled significantly more detail from the film. Awareness of change was also significantly related to content recall scores and accuracy of identification of both burglars. The results illustrate the interrelation between the eyewitness and change blindness literatures.

  10. Demonstration of blind quantum computing.

    PubMed

    Barz, Stefanie; Kashefi, Elham; Broadbent, Anne; Fitzsimons, Joseph F; Zeilinger, Anton; Walther, Philip

    2012-01-20

    Quantum computers, besides offering substantial computational speedups, are also expected to preserve the privacy of a computation. We present an experimental demonstration of blind quantum computing in which the input, computation, and output all remain unknown to the computer. We exploit the conceptual framework of measurement-based quantum computation that enables a client to delegate a computation to a quantum server. Various blind delegated computations, including one- and two-qubit gates and the Deutsch and Grover quantum algorithms, are demonstrated. The client only needs to be able to prepare and transmit individual photonic qubits. Our demonstration is crucial for unconditionally secure quantum cloud computing and might become a key ingredient for real-life applications, especially when considering the challenges of making powerful quantum computers widely available.

  11. The blindness of John Milton.

    PubMed

    Bartley, G B

    1993-04-01

    John Milton (1608-1674) has often been regarded as the greatest poet of his time, yet he did not compose his most famous work, Paradise Lost, until after he had become blind in both eyes. On the basis of clues in Milton's writings, several possible diagnoses have been advanced to explain his loss of vision. Herein the evidence for and against each theory is presented.

  12. The blindness of John Milton.

    PubMed

    Bartley, G B

    1995-01-01

    John Milton (1608-1674) often has been regarded as the greatest poet of his time, yet he did not compose his most famous work, Paradise Lost, until after he had become blind in both eyes. On the basis of clues in Milton's writings, several possible diagnoses have been advanced to explain his loss of vision. The evidence for and against each theory is presented.

  13. Sensory Augmentation for the Blind

    PubMed Central

    Kärcher, Silke M.; Fenzlaff, Sandra; Hartmann, Daniela; Nagel, Saskia K.; König, Peter

    2012-01-01

    Common navigational aids used by blind travelers during large-scale navigation divert attention away from important cues of the immediate environment (i.e., approaching vehicles). Sensory augmentation devices, relying on principles similar to those at work in sensory substitution, can potentially bypass the bottleneck of attention through sub-cognitive implementation of a set of rules coupling motor actions with sensory stimulation. We provide a late blind subject with a vibrotactile belt that continually signals the direction of magnetic north. The subject completed a set of behavioral tests before and after an extended training period. The tests were complemented by questionnaires and interviews. This newly supplied information improved performance on different time scales. In a pointing task we demonstrate an instant improvement of performance based on the signal provided by the device. Furthermore, the signal was helpful in relevant daily tasks, often complicated for the blind, such as keeping a direction over longer distances or taking shortcuts in familiar environments. A homing task with an additional attentional load demonstrated a significant improvement after training. The subject found the directional information highly expedient for the adjustment of his inner maps of familiar environments and describes an increase in his feeling of security when exploring unfamiliar environments with the belt. The results give evidence for a firm integration of the newly supplied signals into the behavior of this late blind subject with better navigational performance and more courageous behavior in unfamiliar environments. Most importantly, the complementary information provided by the belt lead to a positive emotional impact with enhanced feeling of security. The present experimental approach demonstrates the positive potential of sensory augmentation devices for the help of handicapped people. PMID:22403535

  14. Can baseball improve balance in blind subjects?

    PubMed

    Marini, M; Sarchielli, E; Portas, M F; Ranieri, V; Meli, A; Piazza, M; Sgambati, E; Monaci, M

    2011-06-01

    Baseball, one of the most popular sports in the world, is a fast-moving sport that requires various motor abilities. Baseball is played also by blind subjects that participate in many other sports. In this study, we evaluated the role of the Italian modified version of baseball for blind subjects on balance. This modified version of baseball maintains the fast-moving characteristic ensuring the athlete safety. Forty total blind subjects were enrolled: 20 baseball athletes and 20 sedentary participants, as control. The balance was evaluated using the Fukuda Test and Tinetti Test, both in silence and in noise. This baseball game may help to improve the balance ability in blind subjects. The balance was significantly improved in blind athletes as compared with blind sedentary subjects. Given the peculiar characteristics of play, this modified version of baseball seems effective in improving various motor skills that, once transferred into daily activities, may significantly ameliorate the quality of life of blind subjects.

  15. Blind Identification of Graph Filters

    NASA Astrophysics Data System (ADS)

    Segarra, Santiago; Mateos, Gonzalo; Marques, Antonio G.; Ribeiro, Alejandro

    2017-03-01

    Network processes are often represented as signals defined on the vertices of a graph. To untangle the latent structure of such signals, one can view them as outputs of linear graph filters modeling underlying network dynamics. This paper deals with the problem of joint identification of a graph filter and its input signal, thus broadening the scope of classical blind deconvolution of temporal and spatial signals to the less-structured graph domain. Given a graph signal $\\mathbf{y}$ modeled as the output of a graph filter, the goal is to recover the vector of filter coefficients $\\mathbf{h}$, and the input signal $\\mathbf{x}$ which is assumed to be sparse. While $\\mathbf{y}$ is a bilinear function of $\\mathbf{x}$ and $\\mathbf{h}$, the filtered graph signal is also a linear combination of the entries of the lifted rank-one, row-sparse matrix $\\mathbf{x} \\mathbf{h}^T$. The blind graph-filter identification problem can thus be tackled via rank and sparsity minimization subject to linear constraints, an inverse problem amenable to convex relaxations offering provable recovery guarantees under simplifying assumptions. Numerical tests using both synthetic and real-world networks illustrate the merits of the proposed algorithms, as well as the benefits of leveraging multiple signals to aid the blind identification task.

  16. Blind Deconvolution With Model Discrepancies.

    PubMed

    Kotera, Jan; Smidl, Vaclav; Sroubek, Filip

    2017-05-01

    Blind deconvolution is a strongly ill-posed problem comprising of simultaneous blur and image estimation. Recent advances in prior modeling and/or inference methodology led to methods that started to perform reasonably well in real cases. However, as we show here, they tend to fail if the convolution model is violated even in a small part of the image. Methods based on variational Bayesian inference play a prominent role. In this paper, we use this inference in combination with the same prior for noise, image, and blur that belongs to the family of independent non-identical Gaussian distributions, known as the automatic relevance determination prior. We identify several important properties of this prior useful in blind deconvolution, namely, enforcing non-negativity of the blur kernel, favoring sharp images over blurred ones, and most importantly, handling non-Gaussian noise, which, as we demonstrate, is common in real scenarios. The presented method handles discrepancies in the convolution model, and thus extends applicability of blind deconvolution to real scenarios, such as photos blurred by camera motion and incorrect focus.

  17. Justifications shape ethical blind spots.

    PubMed

    Pittarello, Andrea; Leib, Margarita; Gordon-Hecker, Tom; Shalvi, Shaul

    2015-06-01

    To some extent, unethical behavior results from people's limited attention to ethical considerations, which results in an ethical blind spot. Here, we focus on the role of ambiguity in shaping people's ethical blind spots, which in turn lead to their ethical failures. We suggest that in ambiguous settings, individuals' attention shifts toward tempting information, which determines the magnitude of their lies. Employing a novel ambiguous-dice paradigm, we asked participants to report the outcome of the die roll appearing closest to the location of a previously presented fixation cross on a computer screen; this outcome would determine their pay. We varied the value of the die second closest to the fixation cross to be either higher (i.e., tempting) or lower (i.e., not tempting) than the die closest to the fixation cross. Results of two experiments revealed that in ambiguous settings, people's incorrect responses were self-serving. Tracking participants' eye movements demonstrated that people's ethical blind spots are shaped by increased attention toward tempting information.

  18. Isolation and genetic characterisation of Toxoplasma gondii from a red-handed howler monkey (Alouatta belzebul), a jaguarundi (Puma yagouaroundi), and a black-eared opossum (Didelphis aurita) from Brazil.

    PubMed

    Pena, H F J; Marvulo, M F V; Horta, M C; Silva, M A; Silva, J C R; Siqueira, D B; Lima, P-A C P; Vitaliano, S N; Gennari, S M

    2011-02-10

    Toxoplasma gondii isolates are highly diverse in domestic animals from Brazil. However, little is known about the genetics of this parasite from wild mammals in the same region. Reveal genetic similarity or difference of T. gondii among different animal populations is necessary for us to understand transmission of this parasite. Here we reported isolation and genetic characterisation of three T. gondii isolates from wild animals in Brazil. The parasite was isolated by bioassay in mice from tissues of a young male red handed howler monkey (Alouatta belzebul), an adult male jaguarundi (Puma yagouaroundi), and an adult female black-eared opossum (Didelphis aurita). The monkey and the jaguarundi had inhabited the Zoo of Parque Estadual Dois Irmãos, Pernambuco State, Northeastern Brazil, for 1 year and 8 years, respectively. The wild black-eared opossum was captured in São Paulo State, Southeastern Brazil, and euthanised for this study because it was seropositive for T. gondii (titre 1:100 by the modified agglutination test, MAT). Ten PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) markers, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico, were used to genotype the isolates. T. gondii was isolated from the brain and heart homogenate of the monkey, the muscle homogenate of the jaguarundi, and the heart homogenate of the black-eared opossum. This was the first isolation of T. gondii from a neotropical felid from Brazil. The isolate from the monkey (TgRhHmBr1) was not virulent in mice, whereas the isolates from the jaguarundi (TgJagBr1) and the black-eared opossum (TgOpBr1) were virulent in mice. The genotype of the isolate from the monkey has been identified in isolates from a goat and ten chickens in the same region of Brazil, suggesting that it may be a common lineage circulating in this region. The genotypes of the isolates from the jaguarundi and the black-eared opossum have not been previously reported. Although there

  19. Eco-epidemiological study of an endemic Chagas disease region in northern Colombia reveals the importance of Triatoma maculata (Hemiptera: Reduviidae), dogs and Didelphis marsupialis in Trypanosoma cruzi maintenance.

    PubMed

    Cantillo-Barraza, Omar; Garcés, Edilson; Gómez-Palacio, Andrés; Cortés, Luis A; Pereira, André; Marcet, Paula L; Jansen, Ana M; Triana-Chávez, Omar

    2015-09-22

    In Colombia, Rhodnius prolixus and Triatoma dimidiata are the main domestic triatomine species known to transmit T. cruzi. However, there are multiple reports of T. cruzi transmission involving secondary vectors. In this work, we carried out an eco-epidemiological study on Margarita Island, located in the Caribbean region of Colombia, where Chagas disease is associated with non-domiciliated vectors. To understand the transmission dynamics of Trypanosoma cruzi in this area, we designed a comprehensive, multi-faceted study including the following: (i) entomological evaluation through a community-based insect-surveillance campaign, blood meal source determination and T. cruzi infection rate estimation in triatomine insects; (ii) serological determination of T. cruzi prevalence in children under 15 years old, as well as in domestic dogs and synanthropic mammals; (iii) evaluation of T. cruzi transmission capacity in dogs and Didelphis marsupialis, and (iv) genetic characterization of T. cruzi isolates targeting spliced-leader intergene region (SL-IR) genotypes. Out of the 124 triatomines collected, 94% were Triatoma maculata, and 71.6% of them were infected with T. cruzi. Blood-meal source analysis showed that T. maculata feeds on multiple hosts, including humans and domestic dogs. Serological analysis indicated 2 of 803 children were infected, representing a prevalence of 0.25%. The prevalence in domestic dogs was 71.6% (171/224). Domestic dogs might not be competent reservoir hosts, as inferred from negative T. cruzi xenodiagnosis and haemoculture tests. However, 61.5% (8/13) of D. marsupialis, the most abundant synanthropic mammal captured, were T. cruzi-positive on xenodiagnosis and haemocultures. This study reveals the role of peridomestic T. maculata and dogs in T. cruzi persistence in this region and presents evidence that D. marsupialis are a reservoir mediating peridomestic-zoonotic cycles. This picture reflects the complexity of the transmission dynamics of T

  20. Change blindness, aging, and cognition

    PubMed Central

    Rizzo, Matthew; Sparks, JonDavid; McEvoy, Sean; Viamonte, Sarah; Kellison, Ida; Vecera, Shaun P.

    2011-01-01

    Change blindness (CB), the inability to detect changes in visual scenes, may increase with age and early Alzheimer’s disease (AD). To test this hypothesis, participants were asked to localize changes in natural scenes. Dependent measures were response time (RT), hit rate, false positives (FP), and true sensitivity (d′). Increased age correlated with increased sensitivity and RT; AD predicted even slower RT. Accuracy and RT were negatively correlated. Differences in FP were nonsignificant. CB correlated with impaired attention, working memory, and executive function. Advanced age and AD were associated with increased CB, perhaps due to declining memory and attention. CB could affect real-world tasks, like automobile driving. PMID:19051127

  1. Ocular cysticercosis with intermittent blindness.

    PubMed

    Sharma, Rajaram; Dey, Amit Kumar; Joshi, Kapil; Thakkar, Hemangini

    2015-01-01

    We report this peculiar case of ocular cysticercosis with intermittent blindness which is never reported to our knowledge. This case highlights use of Ultrasound for examination of the posterior segment of eye globe. In limited facilities Ultrasound is the main modality to reach the diagnosis. We also wish to enforce the point that in endemic regions and in young population primary cysticercosis and its complications must be kept in differentials of cystic mass or calcified mass, as in this case, we have seen both the stages of cysticercosis progression.

  2. Blindness. [prosthetic devices and sensory aids

    NASA Technical Reports Server (NTRS)

    Pudenz, R. H.

    1974-01-01

    The possibilities are considered that modern electronics and engineering have to offer the individual with a damaged or disordered nervous system, especially the blind person. Discussed are the incidence and principal causes of blindness, past research activities, and a capsule review of some of the more interesting programs designed to provide the blind with the ability to be mobile in their environment and to read printed matter.

  3. Elimination of blinding trachoma in China.

    PubMed

    Liu, T; Liang, Q; Hu, A; Feng, G; Wang, N; Peng, X; Baudouin, C; Labbé, A

    2016-12-01

    To present the change in the prevalence of blindness caused by trachoma between 1987 and 2006 by secondary data analysis based on two China National Sample Surveys on Disability (CNSSD). Secondary data analysis was performed on two China National Sample Surveys on Disability (CNSSD), which were national representative household surveys conducted in 1987 and 2006. The prevalence of blindness caused by trachoma was estimated by 10-year age group. In addition, the proportion of various causes of blindness was evaluated. The geographical distribution of blindness caused by trachoma both in 1987 and 2006 was analyzed in order to visualize the hot spots of blinding trachoma in China. The prevalence of blindness caused by trachoma in China decreased from 51.5/100,000 in 1987 to 17.6/100,000 in 2006. In addition, the proportion of blindness attributed to trachoma also decreased from 10.1% (1987) to 0.9% (2006). Moreover, the prevalence of blindness caused by trachoma was over 200/100,000 in 2.2% of sampled counties in 2006 as compared to 8.6% in 1987. The hot spots of blinding trachoma were shown to be limited to underdeveloped mountain areas in Hubei and Guizhou provinces. Although blinding trachoma is no longer the leading cause of blindness in China since the 2000's, the prevalence of trachoma should still be monitored in some underdeveloped mountain areas. Therefore, health organization must continue to fight against blinding trachoma in underdeveloped areas. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Do perceptions of blindness affect care?

    PubMed

    Orticio, L P

    1994-01-01

    1. Delivery of health care/services is influenced by society's perceptions of blindness. 2. Health care professionals may not be equipped to address inevitable blindness because they may not have been taught how. This lack of preparation during training is a need that must be addressed. 3. The challenge to change inaccurate societal perceptions should start with health professionals--especially those who work with fervor to fight blindness.

  5. Minimum entropy deconvolution and blind equalisation

    NASA Technical Reports Server (NTRS)

    Satorius, E. H.; Mulligan, J. J.

    1992-01-01

    Relationships between minimum entropy deconvolution, developed primarily for geophysics applications, and blind equalization are pointed out. It is seen that a large class of existing blind equalization algorithms are directly related to the scale-invariant cost functions used in minimum entropy deconvolution. Thus the extensive analyses of these cost functions can be directly applied to blind equalization, including the important asymptotic results of Donoho.

  6. Congenital color blindness in young Turkish men.

    PubMed

    Citirik, Mehmet; Acaroglu, Golge; Batman, Cosar; Zilelioglu, Orhan

    2005-04-01

    We investigated a healthy population of men from different regions of Turkey for the presence of congenital red-green color blindness. Using Ishihara pseudoisochromatic plates, 941 healthy men from the Turkish army were tested for congenital red-green color blindness. The prevalence of red-green color blindness was 7.33 +/- 0.98% (5.10% protans and 2.23% deutans). These ratios were higher than other reported samples from Mediterranean Europe. Higher percentages of color blindness were found in regions with a lower education level and more consanguineous marriages.

  7. Astronomy with the color blind

    NASA Astrophysics Data System (ADS)

    Smith, Donald A.; Melrose, Justyn

    2014-12-01

    The standard method to create dramatic color images in astrophotography is to record multiple black and white images, each with a different color filter in the optical path, and then tint each frame with a color appropriate to the corresponding filter. When combined, the resulting image conveys information about the sources of emission in the field, although one should be cautious in assuming that such an image shows what the subject would "really look like" if a person could see it without the aid of a telescope. The details of how the eye processes light have a significant impact on how such images should be understood, and the step from perception to interpretation is even more problematic when the viewer is color blind. We report here on an approach to manipulating stacked tricolor images that, while abandoning attempts to portray the color distribution "realistically," do result in enabling those suffering from deuteranomaly (the most common form of color blindness) to perceive color distinctions they would otherwise not be able to see.

  8. Definition of blindness under National Programme for Control of Blindness: Do we need to revise it?

    PubMed

    Vashist, Praveen; Senjam, Suraj Singh; Gupta, Vivek; Gupta, Noopur; Kumar, Atul

    2017-02-01

    A review appropriateness of the current definition of blindness under National Programme for Control of Blindness (NPCB), Government of India. Online search of peer-reviewed scientific published literature and guidelines using PubMed, the World Health Organization (WHO) IRIS, and Google Scholar with keywords, namely blindness and visual impairment, along with offline examination of reports of national and international organizations, as well as their cross-references was done until December 2016, to identify relevant documents on the definition of blindness. The evidence for the historical and currently adopted definition of blindness under the NPCB, the WHO, and other countries was reviewed. Differences in the NPCB and WHO definitions were analyzed to assess the impact on the epidemiological status of blindness and visual impairment in India. The differences in the criteria for blindness under the NPCB and the WHO definitions cause an overestimation of the prevalence of blindness in India. These variations are also associated with an over-representation of refractive errors as a cause of blindness and an under-representation of other causes under the NPCB definition. The targets for achieving elimination of blindness also become much more difficult to achieve under the NPCB definition. Ignoring differences in definitions when comparing the global and Indian prevalence of blindness will cause erroneous interpretations. We recommend that the appropriate modifications should be made in the NPCB definition of blindness to make it consistent with the WHO definition.

  9. Definition of blindness under National Programme for Control of Blindness: Do we need to revise it?

    PubMed Central

    Vashist, Praveen; Senjam, Suraj Singh; Gupta, Vivek; Gupta, Noopur; Kumar, Atul

    2017-01-01

    A review appropriateness of the current definition of blindness under National Programme for Control of Blindness (NPCB), Government of India. Online search of peer-reviewed scientific published literature and guidelines using PubMed, the World Health Organization (WHO) IRIS, and Google Scholar with keywords, namely blindness and visual impairment, along with offline examination of reports of national and international organizations, as well as their cross-references was done until December 2016, to identify relevant documents on the definition of blindness. The evidence for the historical and currently adopted definition of blindness under the NPCB, the WHO, and other countries was reviewed. Differences in the NPCB and WHO definitions were analyzed to assess the impact on the epidemiological status of blindness and visual impairment in India. The differences in the criteria for blindness under the NPCB and the WHO definitions cause an overestimation of the prevalence of blindness in India. These variations are also associated with an over-representation of refractive errors as a cause of blindness and an under-representation of other causes under the NPCB definition. The targets for achieving elimination of blindness also become much more difficult to achieve under the NPCB definition. Ignoring differences in definitions when comparing the global and Indian prevalence of blindness will cause erroneous interpretations. We recommend that the appropriate modifications should be made in the NPCB definition of blindness to make it consistent with the WHO definition. PMID:28345562

  10. Childhood Fears among Children Who Are Blind: The Perspective of Teachers Who Are Blind

    ERIC Educational Resources Information Center

    Al-Zboon, Eman

    2017-01-01

    The aim of this study was to investigate childhood fears in children who are blind from the perspective of teachers who are blind. The study was conducted in Jordan. Forty-six teachers were interviewed. Results revealed that the main fear content in children who are blind includes fear of the unknown; environment-, transportation- and…

  11. Difference Blindness/Blindness Difference: Student Explorations of "Disability" over the Internet.

    ERIC Educational Resources Information Center

    Murphy, Kelly; And Others

    This case study describes the Internet correspondence using MOO, a multiuser, object-oriented site, that was developed between six third-grade girls and TCC, an adult with blindness. The changes from the students' original attitudes toward blindness, that blindness posed a barrier to communication and relationship-building, into their acceptance…

  12. The Social Life and Blind People. American Foundation for the Blind Research Series No. 19.

    ERIC Educational Resources Information Center

    Josephson, Eric

    Discussions and information are concerned with free time and leisure, age, impairment, and leisure, and poverty and leisure; the prevalence of blindness, the self-perception of the blind, their activity and mobility limitations; and problems of poverty of the blind in education, employment, income, and living arrangements. Also discussed are…

  13. 42 CFR 436.531 - Determination of blindness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Determination of blindness. 436.531 Section 436.531... Requirements for Medicaid Eligibility Blindness § 436.531 Determination of blindness. In determining blindness... determine on behalf of the agency— (1) Whether the individual meets the definition of blindness; and (2...

  14. 42 CFR 436.531 - Determination of blindness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Determination of blindness. 436.531 Section 436.531... Requirements for Medicaid Eligibility Blindness § 436.531 Determination of blindness. In determining blindness... determine on behalf of the agency— (1) Whether the individual meets the definition of blindness; and (2...

  15. 42 CFR 436.531 - Determination of blindness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Determination of blindness. 436.531 Section 436.531... Requirements for Medicaid Eligibility Blindness § 436.531 Determination of blindness. In determining blindness... determine on behalf of the agency— (1) Whether the individual meets the definition of blindness; and (2...

  16. 42 CFR 436.531 - Determination of blindness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Determination of blindness. 436.531 Section 436.531... Requirements for Medicaid Eligibility Blindness § 436.531 Determination of blindness. In determining blindness... determine on behalf of the agency— (1) Whether the individual meets the definition of blindness; and (2...

  17. 42 CFR 436.531 - Determination of blindness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Determination of blindness. 436.531 Section 436.531... Requirements for Medicaid Eligibility Blindness § 436.531 Determination of blindness. In determining blindness... determine on behalf of the agency— (1) Whether the individual meets the definition of blindness; and (2...

  18. Glycoprotein Degradation in the Blind Loop Syndrome

    PubMed Central

    Prizont, Roberto

    1981-01-01

    Contents obtained from jejunum of normal controls, self-emptying and self-filling blind loop rats were analyzed for the presence of glycoprotein-degrading glycosidases. The blind loop syndrome was documented by the increased fat excretion and slower growth rate of self-filling blind loop rats 6 wk after surgery. With p-nitrophenylglycosides as substrate, the specific activity of α-N-acetylgalactosaminidase, a potential blood group A destroying glycosidase, was 0.90±0.40 mU/mg of protein. This level was 23-fold higher than the specific activity of normal controls. In partially purified self-filling blind loop contents, the activity of α-N-acetylgalactosaminidase was 9- to 70-fold higher than activities of self-emptying and normal controls. Antibiotic treatment with chloromycetin and polymyxin decreased 24-fold the glycosidase levels in self-filling blind loops. In experiments with natural substrate, the blood group A titer of a20,000g supernate from normal jejunal homogenates decreased 128-fold after 24-h incubation with blind loop contents. Normal contents failed to diminish the blood group reactivity of the natural substrate. Furthermore, blind loop contents markedly decreased the blood group A titer of isolated brush borders. Incubation between blind loop bacteria and mucosal homogenates or isolated brush borders labeled with d-[U-14C]glucosamine revealed increased production of labeled ether extractable organic acids. Likewise, intraperitoneal injection of d-[U-14C]glucosamine into self-filling blind loop rats resulted in incorporation of the label into luminal short chain fatty acids. These results suggest that glycosidases may provide a mechanism by which blind loop bacteria obtain sugars from intestinal glycoproteins. The released sugars are used and converted by bacteria into energy and organic acids. This use of the host's glycoproteins would allow blind loop bacteria to grow and survive within the lumen independent of exogenous sources. PMID:6257760

  19. Public-Facilities Locator For The Blind

    NASA Technical Reports Server (NTRS)

    Moore, Kevin D.

    1988-01-01

    Proposed optoelectronic system guides blind people to important locations in public buildings, With system, sightless person easily determines directions and distances of restrooms, water fountains, stairways, emergency exits, and elevators. Circuitry uncomplicated and inexpensive, in both transmitter and receiver. Readily-available light-emitting diodes, photodiodes, and integrated-circuit chips used to build locator aid for the blind.

  20. Individual Differences in Susceptibility to Inattentional Blindness

    ERIC Educational Resources Information Center

    Seegmiller, Janelle K.; Watson, Jason M.; Strayer, David L.

    2011-01-01

    Inattentional blindness refers to the finding that people do not always see what appears in their gaze. Though inattentional blindness affects large percentages of people, it is unclear if there are individual differences in susceptibility. The present study addressed whether individual differences in attentional control, as reflected by…

  1. Mentoring Transition-Age Youth with Blindness

    ERIC Educational Resources Information Center

    Bell, Edward C.

    2012-01-01

    This article reports on a mentoring project designed for transition-age youth (ages 16-26) who are persons with legal blindness. Youth were matched with adult mentors who were also persons with blindness but who have achieved academic and career success. Results demonstrate that youth who participated in the project for 2 years had significant…

  2. Blind Children's Concepts of How People See.

    ERIC Educational Resources Information Center

    Bigelow, A.

    1988-01-01

    The concepts of two totally blind children, ages four and five, concerning how people see, were evaluated by asking them to show objects to either sighted people or each other. Their performance indicated they understood that blind people need to feel objects but sighted persons do not. (Author/DB)

  3. Mental Imagery in Congenitally Blind Children.

    ERIC Educational Resources Information Center

    Anderson, David W.

    1986-01-01

    A study explored the nature of representational thought in 10 congenitally blind three- to nine-year-olds through interviews during which the subjects defined and described objects and later identified similar objects. Results suggested that blind children should be taught appropriate or systematic methods for tactually obtaining information. (CB)

  4. Semantic and Phonemic Verbal Fluency in Blinds

    ERIC Educational Resources Information Center

    Nejati, Vahid; Asadi, Anoosh

    2010-01-01

    A person who has suffered the total loss of a sensory system has, indirectly, suffered a brain lesion. Semantic and phonologic verbal fluency are used for evaluation of executive function and language. The aim of this study is evaluation and comparison of phonemic and semantic verbal fluency in acquired blinds. We compare 137 blinds and 124…

  5. Semantic and Phonemic Verbal Fluency in Blinds

    ERIC Educational Resources Information Center

    Nejati, Vahid; Asadi, Anoosh

    2010-01-01

    A person who has suffered the total loss of a sensory system has, indirectly, suffered a brain lesion. Semantic and phonologic verbal fluency are used for evaluation of executive function and language. The aim of this study is evaluation and comparison of phonemic and semantic verbal fluency in acquired blinds. We compare 137 blinds and 124…

  6. Individual Differences in Susceptibility to Inattentional Blindness

    ERIC Educational Resources Information Center

    Seegmiller, Janelle K.; Watson, Jason M.; Strayer, David L.

    2011-01-01

    Inattentional blindness refers to the finding that people do not always see what appears in their gaze. Though inattentional blindness affects large percentages of people, it is unclear if there are individual differences in susceptibility. The present study addressed whether individual differences in attentional control, as reflected by…

  7. Mentoring Transition-Age Youth with Blindness

    ERIC Educational Resources Information Center

    Bell, Edward C.

    2012-01-01

    This article reports on a mentoring project designed for transition-age youth (ages 16-26) who are persons with legal blindness. Youth were matched with adult mentors who were also persons with blindness but who have achieved academic and career success. Results demonstrate that youth who participated in the project for 2 years had significant…

  8. Wayfinding Information for Congenitally Blind Individuals.

    ERIC Educational Resources Information Center

    Passini, R.; And Others

    1988-01-01

    Fifteen congenitally blind subjects were involved in a route-finding experiment in a complex architectural setting. Compared to sighted controls, subjects planned the journey in more detail, formulated more decisions, and used more units of information. On a cognitive mapping exercise, the blind subjects performed virtually as well as sighted…

  9. Deaf-Blind Perspectives, 2000-2001.

    ERIC Educational Resources Information Center

    Malloy, Peggy, Ed.

    2001-01-01

    These three issues of "Deaf-Blind Perspectives" feature the following articles: (1) "A Group for Students with Usher Syndrome in South Louisiana" (Faye Melancon); (2) "Simply Emily," which discusses a budding friendship between a girl with deaf-blindness and a peer; (3) "Intervener Update" (Peggy Malloy and…

  10. Vision Science: Can Rhodopsin Cure Blindness?

    PubMed

    Van Gelder, Russell N; Kaur, Kuldeep

    2015-08-17

    Outer retinal degeneration is the leading cause of blindness in the developed world. A new study now demonstrates that ectopic expression of human rhodopsin in the inner retina, mediated by viral gene therapy, can restore light sensitivity and some vision to mice blind from outer retinal degeneration.

  11. New Identity-Based Blind Signature and Blind Decryption Scheme in the Standard Model

    NASA Astrophysics Data System (ADS)

    Phong, Le Trieu; Ogata, Wakaha

    We explicitly describe and analyse blind hierachical identity-based encryption (blind HIBE) schemes, which are natural generalizations of blind IBE schemes [20]. We then uses the blind HIBE schemes to construct: (1) An identity-based blind signature scheme secure in the standard model, under the computational Diffie-Hellman (CDH) assumption, and with much shorter signature size and lesser communication cost, compared to existing proposals. (2) A new mechanism supporting a user to buy digital information over the Internet without revealing what he/she has bought, while protecting the providers from cheating users.

  12. Blindness in designing intelligent systems

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1988-01-01

    New investigations of the foundations of artificial intelligence are challenging the hypothesis that problem solving is the cornerstone of intelligence. New distinctions among three domains of concern for humans--description, action, and commitment--have revealed that the design process for programmable machines, such as expert systems, is based on descriptions of actions and induces blindness to nonanalytic action and commitment. Design processes focusing in the domain of description are likely to yield programs like burearcracies: rigid, obtuse, impersonal, and unable to adapt to changing circumstances. Systems that learn from their past actions, and systems that organize information for interpretation by human experts, are more likely to be successful in areas where expert systems have failed.

  13. The PHENIX Hadron Blind Detector

    SciTech Connect

    Durham, J. M.

    2009-03-10

    Dielectron measurements by the PHENIX Experiment at RHIC are limited by the combinatorial background from electrons and positrons which are not produced in the same pair. The Hadron Blind Detector will allow a substantial reduction of this background by correctly identifying dielectrons from photon conversions and pion Dalitz decays which dominate the signal in the low mass region of the spectrum. Triple GEM stacks, with a CsI photocathode deposited on the uppermost GEM, detect Cherenkov light produced by electrons in a CF{sub 4} radiator. The transparency of CF{sub 4}, high quantum efficiency of CsI in the UV, and absence of a window between the gas radiator and the GEMs allow a large photoelectron yield, while minimizing the hadron signal. Results from the HBD in RHIC's Run-7 and preparations for upcoming runs are discussed.

  14. Combined Superresolution and Blind Deconvolution

    NASA Astrophysics Data System (ADS)

    Šroubek, Filip; Cristóbal, Gabriel; Flusser, Jan

    2006-10-01

    This paper presents a unifying approach to the blind deconvolution and superresolution problem of multiple degraded low-resolution frames of the original scene. We do not assume any prior information about the shape of degradation blurs. The proposed approach consists of building a regularized energy function and minimizing it with respect to the original image and blurs, where regularization is carried out in both the image and blur domains. The image regularization based on variational principles maintains stable performance under severe noise corruption. The blur regularization guarantees consistency of the solution by exploiting differences among the acquired low-resolution images. Experiments on real data illustrate the robustness and utilization of the proposed technique.

  15. Efficient Universal Blind Quantum Computation

    NASA Astrophysics Data System (ADS)

    Giovannetti, Vittorio; Maccone, Lorenzo; Morimae, Tomoyuki; Rudolph, Terry G.

    2013-12-01

    We give a cheat sensitive protocol for blind universal quantum computation that is efficient in terms of computational and communication resources: it allows one party to perform an arbitrary computation on a second party’s quantum computer without revealing either which computation is performed, or its input and output. The first party’s computational capabilities can be extremely limited: she must only be able to create and measure single-qubit superposition states. The second party is not required to use measurement-based quantum computation. The protocol requires the (optimal) exchange of O(Jlog⁡2(N)) single-qubit states, where J is the computational depth and N is the number of qubits needed for the computation.

  16. Auditory display for the blind

    NASA Technical Reports Server (NTRS)

    Fish, R. M. (Inventor)

    1974-01-01

    A system for providing an auditory display of two-dimensional patterns as an aid to the blind is described. It includes a scanning device for producing first and second voltages respectively indicative of the vertical and horizontal positions of the scan and a further voltage indicative of the intensity at each point of the scan and hence of the presence or absence of the pattern at that point. The voltage related to scan intensity controls transmission of the sounds to the subject so that the subject knows that a portion of the pattern is being encountered by the scan when a tone is heard, the subject determining the position of this portion of the pattern in space by the frequency and interaural difference information contained in the tone.

  17. Efficient universal blind quantum computation.

    PubMed

    Giovannetti, Vittorio; Maccone, Lorenzo; Morimae, Tomoyuki; Rudolph, Terry G

    2013-12-06

    We give a cheat sensitive protocol for blind universal quantum computation that is efficient in terms of computational and communication resources: it allows one party to perform an arbitrary computation on a second party's quantum computer without revealing either which computation is performed, or its input and output. The first party's computational capabilities can be extremely limited: she must only be able to create and measure single-qubit superposition states. The second party is not required to use measurement-based quantum computation. The protocol requires the (optimal) exchange of O(Jlog2(N)) single-qubit states, where J is the computational depth and N is the number of qubits needed for the computation.

  18. Unconditionally verifiable blind quantum computation

    NASA Astrophysics Data System (ADS)

    Fitzsimons, Joseph F.; Kashefi, Elham

    2017-07-01

    Blind quantum computing (BQC) allows a client to have a server carry out a quantum computation for them such that the client's input, output, and computation remain private. A desirable property for any BQC protocol is verification, whereby the client can verify with high probability whether the server has followed the instructions of the protocol or if there has been some deviation resulting in a corrupted output state. A verifiable BQC protocol can be viewed as an interactive proof system leading to consequences for complexity theory. We previously proposed [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual Symposium on Foundations of Computer Science, Atlanta, 2009 (IEEE, Piscataway, 2009), p. 517] a universal and unconditionally secure BQC scheme where the client only needs to be able to prepare single qubits in separable states randomly chosen from a finite set and send them to the server, who has the balance of the required quantum computational resources. In this paper we extend that protocol with additional functionality allowing blind computational basis measurements, which we use to construct another verifiable BQC protocol based on a different class of resource states. We rigorously prove that the probability of failing to detect an incorrect output is exponentially small in a security parameter, while resource overhead remains polynomial in this parameter. This resource state allows entangling gates to be performed between arbitrary pairs of logical qubits with only constant overhead. This is a significant improvement on the original scheme, which required that all computations to be performed must first be put into a nearest-neighbor form, incurring linear overhead in the number of qubits. Such an improvement has important consequences for efficiency and fault-tolerance thresholds.

  19. Subcortical functional reorganization due to early blindness.

    PubMed

    Coullon, Gaelle S L; Jiang, Fang; Fine, Ione; Watkins, Kate E; Bridge, Holly

    2015-04-01

    Lack of visual input early in life results in occipital cortical responses to auditory and tactile stimuli. However, it remains unclear whether cross-modal plasticity also occurs in subcortical pathways. With the use of functional magnetic resonance imaging, auditory responses were compared across individuals with congenital anophthalmia (absence of eyes), those with early onset (in the first few years of life) blindness, and normally sighted individuals. We find that the superior colliculus, a "visual" subcortical structure, is recruited by the auditory system in congenital and early onset blindness. Additionally, auditory subcortical responses to monaural stimuli were altered as a result of blindness. Specifically, responses in the auditory thalamus were equally strong to contralateral and ipsilateral stimulation in both groups of blind subjects, whereas sighted controls showed stronger responses to contralateral stimulation. These findings suggest that early blindness results in substantial reorganization of subcortical auditory responses. Copyright © 2015 the American Physiological Society.

  20. Tactile maze solving in congenitally blind individuals.

    PubMed

    Gagnon, Léa; Kupers, Ron; Schneider, Fabien C; Ptito, Maurice

    2010-10-27

    Vision is undoubtedly important for navigation although not essential as blind individuals outperform their blindfolded seeing counterparts in a variety of navigational tasks. It is believed that the blind's superior performance is because of their efficient use of proprioceptive signals and environmental cues such as temperature and echolocation. We hypothesize that by limiting these cues, blind individuals will lose their advantage compared with controls in spatial navigation tasks. We therefore evaluated the performance of blind and sighted individuals in small-scale, tactile multiple T mazes. Our results show that blindfolded sighted controls outperformed blind participants in the route-learning tasks. This suggests that, contrary to indoor large-scale spaces, navigational skills inside small-scale spaces benefit from visual experience.

  1. Blind Braille readers mislocate tactile stimuli.

    PubMed

    Sterr, Annette; Green, Lisa; Elbert, Thomas

    2003-05-01

    In a previous experiment, we observed that blind Braille readers produce errors when asked to identify on which finger of one hand a light tactile stimulus had occurred. With the present study, we aimed to specify the characteristics of this perceptual error in blind and sighted participants. The experiment confirmed that blind Braille readers mislocalised tactile stimuli more often than sighted controls, and that the localisation errors occurred significantly more often at the right reading hand than at the non-reading hand. Most importantly, we discovered that the reading fingers showed the smallest error frequency, but the highest rate of stimulus attribution. The dissociation of perceiving and locating tactile stimuli in the blind suggests altered tactile information processing. Neuroplasticity, changes in tactile attention mechanisms as well as the idea that blind persons may employ different strategies for tactile exploration and object localisation are discussed as possible explanations for the results obtained.

  2. Continuous-Variable Blind Quantum Computation

    NASA Astrophysics Data System (ADS)

    Morimae, Tomoyuki

    2012-12-01

    Blind quantum computation is a secure delegated quantum computing protocol where Alice, who does not have sufficient quantum technology at her disposal, delegates her computation to Bob, who has a fully fledged quantum computer, in such a way that Bob cannot learn anything about Alice’s input, output, and algorithm. Protocols of blind quantum computation have been proposed for several qudit measurement-based computation models, such as the graph state model, the Affleck-Kennedy-Lieb-Tasaki model, and the Raussendorf-Harrington-Goyal topological model. Here, we consider blind quantum computation for the continuous-variable measurement-based model. We show that blind quantum computation is possible for the infinite squeezing case. We also show that the finite squeezing causes no additional problem in the blind setup apart from the one inherent to the continuous-variable measurement-based quantum computation.

  3. Blindness and severe visual impairment in pupils at schools for the blind in Burundi.

    PubMed

    Ruhagaze, Patrick; Njuguna, Kahaki Kimani Margaret; Kandeke, Lévi; Courtright, Paul

    2013-01-01

    To determine the causes of childhood blindness and severe visual impairment in pupils attending schools for the blind in Burundi in order to assist planning for services in the country. All pupils attending three schools for the blind in Burundi were examined. A modified WHO/PBL eye examination record form for children with blindness and low vision was used to record the findings. Data was analyzed for those who became blind or severely visually impaired before the age of 16 years. Overall, 117 pupils who became visually impaired before 16 years of age were examined. Of these, 109 (93.2%) were blind or severely visually impaired. The major anatomical cause of blindness or severe visual impairment was cornea pathology/phthisis (23.9%), followed by lens pathology (18.3%), uveal lesions (14.7%) and optic nerve lesions (11.9%). In the majority of pupils with blindness or severe visual impairment, the underlying etiology of visual loss was unknown (74.3%). More than half of the pupils with lens related blindness had not had surgery; among those who had surgery, outcomes were generally poor. The causes identified indicate the importance of continuing preventive public health strategies, as well as the development of specialist pediatric ophthalmic services in the management of childhood blindness in Burundi. The geographic distribution of pupils at the schools for the blind indicates a need for community-based programs to identify and refer children in need of services.

  4. Blindness and Severe Visual Impairment in Pupils at Schools for the Blind in Burundi

    PubMed Central

    Ruhagaze, Patrick; Njuguna, Kahaki Kimani Margaret; Kandeke, Lévi; Courtright, Paul

    2013-01-01

    Purpose: To determine the causes of childhood blindness and severe visual impairment in pupils attending schools for the blind in Burundi in order to assist planning for services in the country. Materials and Methods: All pupils attending three schools for the blind in Burundi were examined. A modified WHO/PBL eye examination record form for children with blindness and low vision was used to record the findings. Data was analyzed for those who became blind or severely visually impaired before the age of 16 years. Results: Overall, 117 pupils who became visually impaired before 16 years of age were examined. Of these, 109 (93.2%) were blind or severely visually impaired. The major anatomical cause of blindness or severe visual impairment was cornea pathology/phthisis (23.9%), followed by lens pathology (18.3%), uveal lesions (14.7%) and optic nerve lesions (11.9%). In the majority of pupils with blindness or severe visual impairment, the underlying etiology of visual loss was unknown (74.3%). More than half of the pupils with lens related blindness had not had surgery; among those who had surgery, outcomes were generally poor. Conclusion: The causes identified indicate the importance of continuing preventive public health strategies, as well as the development of specialist pediatric ophthalmic services in the management of childhood blindness in Burundi. The geographic distribution of pupils at the schools for the blind indicates a need for community-based programs to identify and refer children in need of services. PMID:23580854

  5. Genetics Home Reference: autosomal dominant congenital stationary night blindness

    MedlinePlus

    ... stationary night blindness autosomal dominant congenital stationary night blindness Printable PDF Open All Close All Enable Javascript ... collapse boxes. Description Autosomal dominant congenital stationary night blindness is a disorder of the retina , which is ...

  6. Genetics Home Reference: autosomal recessive congenital stationary night blindness

    MedlinePlus

    ... stationary night blindness autosomal recessive congenital stationary night blindness Printable PDF Open All Close All Enable Javascript ... collapse boxes. Description Autosomal recessive congenital stationary night blindness is a disorder of the retina , which is ...

  7. As World's Population Ages, Blindness Rates Likely to Grow

    MedlinePlus

    ... news/fullstory_167592.html As World's Population Ages, Blindness Rates Likely to Grow Study of 188 countries ... are blind. The study added that rates of blindness among older adults are highest in eastern and ...

  8. Genetics Home Reference: X-linked congenital stationary night blindness

    MedlinePlus

    ... stationary night blindness X-linked congenital stationary night blindness Printable PDF Open All Close All Enable Javascript ... collapse boxes. Description X-linked congenital stationary night blindness is a disorder of the retina , which is ...

  9. Individual and team susceptibility to change blindness.

    PubMed

    Tollner-Burngasser, Alison; Riley, Michael A; Nelson, W Todd

    2010-10-01

    Individual operators in command and control environments are susceptible to change blindness. Change blindness by teams of operators, which is typical in military command and control, has not been extensively studied. This experiment investigated change blindness in individuals and teams in a simulated military command and control situation display. Subjects completed a change-detection task individually or in three-person teams. In one team condition team members could actively communicate with each other, but in another condition they could not. The change-detection task involved monitoring flicker sequences of displays containing 6, 12, 24, or 48 icons for changes in icon position. Results revealed a team advantage that was more pronounced when teams communicated. Communicating teams had higher overall correct detection rates (mean = 95%) than both non-communicating triads (mean = 80%) and individuals (mean = 79%). Teams were susceptible to change blindness just as individuals were, but teamwork and communication were beneficial in reducing change blindness susceptibility. Communicating teams also experienced lower global workload (mean = 24.08) than non-communicating triads (mean = 38.44) and individuals (mean = 47.18). This research highlights the importance of teamwork and communication in reducing change blindness and workload in a command and control environment. The findings can be used to facilitate development of methods and tools for reducing individual and team change blindness susceptibility.

  10. Auditory Spatial Recalibration in Congenital Blind Individuals

    PubMed Central

    Finocchietti, Sara; Cappagli, Giulia; Gori, Monica

    2017-01-01

    Blind individuals show impairments for auditory spatial skills that require complex spatial representation of the environment. We suggest that this is partially due to the egocentric frame of reference used by blind individuals. Here we investigate the possibility of reducing the mentioned auditory spatial impairments with an audio-motor training. Our hypothesis is that the association between a motor command and the corresponding movement's sensory feedback can provide an allocentric frame of reference and consequently help blind individuals in understanding complex spatial relationships. Subjects were required to localize the end point of a moving sound before and after either 2-min of audio-motor training or a complete rest. During the training, subjects were asked to move their hand, and consequently the sound source, to freely explore the space around the setup and the body. Both congenital blind (N = 20) and blindfolded healthy controls (N = 28) participated in the study. Results suggest that the audio-motor training was effective in improving space perception of blind individuals. The improvement was not observed in those subjects that did not perform the training. This study demonstrates that it is possible to recalibrate the auditory spatial representation in congenital blind individuals with a short audio-motor training and provides new insights for rehabilitation protocols in blind people. PMID:28261053

  11. Blindness prevention programmes: past, present, and future.

    PubMed Central

    Resnikoff, S.; Pararajasegaram, R.

    2001-01-01

    Blindness and visual impairment have far-reaching implications for society, the more so when it is realized that 80% of visual disability is avoidable. The marked increase in the size of the elderly population, with their greater propensity for visually disabling conditions, presents a further challenge in this respect. However, if available knowledge and skills were made accessible to those communities in greatest need, much of this needless blindness could be alleviated. Since its inception over 50 years ago, and beginning with trachoma control, WHO has spearheaded efforts to assist Member States to meet the challenge of needless blindness. Since the establishment of the WHO Programme for the Prevention of Blindness in 1978, vast strides have been made through various forms of technical support to establish national prevention of blindness programmes. A more recent initiative, "The Global Initiative for the Elimination of Avoidable Blindness" (referred to as "VISION 2020--The Right to Sight"), launched in 1999, is a collaborative effort between WHO and a number of international nongovernmental organizations and other interested partners. This effort is poised to take the steps necessary to achieve the goal of eliminating avoidable blindness worldwide by the year 2020. PMID:11285666

  12. Favorable outcome of epileptic blindness in children.

    PubMed

    Shahar, Eli; Barak, Shai

    2003-01-01

    Acute blindness is a rare presentation of epileptic seizures, referring to loss of sight without loss of consciousness associated with electroencephalographic (EEG) epileptic discharges, mainly representing an ictal phase but also either pre- or postictal. We report a series of 14 children with documented epileptic blindness, describing the accompanying fits and thereafter the response to therapy to resolve the blindness and control associated seizures. All patients experienced episodes of acute complete visual obscuration lasting for 1 to 10 minutes. Seven patients hadaccompanying generalized seizures, with a photosensitive response recorded in three of them. All of these seven children were treated with valproic acid, regaining full vision, and six of them became seizure free. Three patients with acute blindness who had accompanying focal motor seizures and unilateral temporooccipital posterior epileptic discharges were treated with carbamazepine regained full vision and complete seizure control. Four additional children had the constellation of migrainous headaches, focal motor phenomena, and complete blindness, along with occipital discharges compatible with Gastaut syndrome, benign childhood epilepsy with occipital paroxysms. All four patients were started on carbamazepine and became asymptomatic. Our overall experience suggests that epileptic blindness in children is associated with a favorable outcome when promptly diagnosed and treated appropriately, resulting in complete resolution of blindness in all children and satisfactory control of seizures in most of them. We therefore recommend performing a prompt EEG in any child presenting with acute visual obscuration, even in the absence of other epileptic phenomena.

  13. Blind extraction of exoplanetary spectra

    NASA Astrophysics Data System (ADS)

    Morello, Giuseppe; Waldmann, Ingo; Damiano, Mario; Tinetti, Giovanna

    2016-10-01

    In the last decade, remote sensing spectroscopy enabled characterization of the atmospheres of extrasolar planets. Transmission and emission spectra of tens of transiting exoplanets have been measured with multiple instruments aboard Spitzer and Hubble Space Telescopes as well as ground-based facilities, revealing the presence of chemical species in their atmospheres, and constraining their temperature and pressure profiles.Early analyses were somehow heuristic, leading to some controversies in the literature.A photometric precision of 0.01% is necessary to detect the atmospheric spectral modulations. Current observatories, except Kepler, were not designed to achieve this precision. Data reduction is necessary to minimize the effect of instrument systematics in order to achieve the target precision. In the past, parametric models have extensively been used by most teams to remove correlated noise with the aid of auxiliary information of the instrument, the so-called optical state vectors (OSVs). Such OSVs can include inter- and intra-pixel position of the star or its spectrum, instrument temperatures and inclinations, and/or other parameters. In some cases, different parameterizations led to discrepant results.We recommend the use of blind non-parametric data detrending techniques to overcome those issues. In particular, we adopt Independent Component Analysis (ICA), i.e. a powerful blind source separation (BSS) technique to disentangle the multiple instrument systematics and astrophysical signals in transit/eclipse light curves. ICA does not require a model for the systematics, thence it can be applied to any instrument with little changes, if any. ICA-based algorithms have been applied to Spitzer/IRAC and synthetic observations in photometry (Morello et al. 2014, 2015, 2016; Morello 2015) and to Hubble/WFC3, Hubble/NICMOS and Spitzer/IRS and Hubble/WFC3 in spectroscopy (Damiano, Morello et al., in prep., Waldmann 2012, 2014, Waldmann et al. 2013) with excellent

  14. Blind extraction of exoplanetary spectra

    NASA Astrophysics Data System (ADS)

    Morello, Giuseppe; Waldmann, Ingo P.; Tinetti, Giovanna

    2016-06-01

    In the last decade, remote sensing spectroscopy enabled characterization of the atmospheres of extrasolar planets. Transmission and emission spectra of tens of transiting exoplanets have been measured with multiple instruments aboard Spitzer and Hubble Space Telescopes as well as ground-based facilities, revealing the presence of atomic, ionic and molecular species in their atmospheres, and constraining their temperature and pressure profiles.Early analyses were somehow heuristic both in measuring the spectra and in their interpretation, leading to some controversies in the literature.A photometric precision of 0.01% is necessary to detect the atmospheric spectral modulations. Current observatories, except Kepler, were not designed to achieve this precision. Data reduction is necessary to minimize the effect of instrument systematics in order to achieve the target precision. In the past, parametric models have extensively been used by most teams to remove correlated noise with the aid of auxiliary information of the instrument, the so-called optical state vectors (OSVs). Such OSVs can include inter- and intra-pixel position of the star or its spectrum, instrument temperatures and inclinations, and/or other parameters. In some cases, different parameterizations led to discrepant results.We recommend the use of blind non-parametric data detrending techniques to overcome those issues. In particular, we adopt Independent Component Analysis (ICA), i.e. a blind source separation (BSS) technique to disentangle the multiple instrument systematics and astrophysical signals in transit/eclipse light curves. ICA does not require a model for the systematics, and for this reason, it can be applied to any instrument with little changes, if any. ICA-based algorithms have been applied to Spitzer/IRAC and synthetic observations in photometry (Morello et al. 2014, 2015, 2016; Morello 2015) and to Hubble/NICMOS and Spitzer/IRS in spectroscopy (Waldmann 2012, 2014, Waldmann et al. 2013

  15. Causes and emerging trends of childhood blindness: findings from schools for the blind in Southeast Nigeria.

    PubMed

    Aghaji, Ada; Okoye, Obiekwe; Bowman, Richard

    2015-06-01

    To ascertain the causes severe visual impairment and blindness (SVI/BL) in schools for the blind in southeast Nigeria and to evaluate temporal trends. All children who developed blindness at <15 years of age in all the three schools for the blind in southeast Nigeria were examined. All the data were recorded on a WHO/Prevention of Blindness (WHO/PBL) form entered into a Microsoft Access database and transferred to STATA V.12.1 for analysis. To estimate temporal trends in causes of blindness, older (>15 years) children were compared with younger (≤15 years) children. 124 children were identified with SVI/BL. The most common anatomical site of blindness was the lens (33.9%). Overall, avoidable blindness accounted for 73.4% of all blindness. Exploring trends in SVI/BL between children ≤15 years of age and those >15 years old, this study shows a reduction in avoidable blindness but an increase in cortical visual impairment in the younger age group. The results from this study show a statistically significant decrease in avoidable blindness in children ≤15 years old. Corneal blindness appears to be decreasing but cortical visual impairment seems to be emerging in the younger age group. Appropriate strategies for the prevention of avoidable childhood blindness in Nigeria need to be developed and implemented. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. Thermal imaging aid for the blind.

    PubMed

    Hedin, D S; Seifert, G J; Dagnelie, G; Havey, G D; Knuesel, R J; Gibson, P L

    2006-01-01

    To explore the efficacy of using a far infrared thermal camera with a haptic display to assist blind people in identifying humans, we performed experiments with a prototype device on five low-vision (functionally blind) subjects. Infrared allows for easy detection of human shape due to typically high contrast in temperatures from a person against their surrounding environment. Infrared cameras can be made small and inexpensive with uncooled microbolometer technology. Our study showed a great willingness by the blind subjects to use such a device after a short training session and both successful and unsuccessful operation. Future work will further develop the technology and undertake more expansive testing.

  17. Kalman Filtering Approach to Blind Equalization

    DTIC Science & Technology

    1993-12-01

    Update weighing probabilities (3.11) vi. Compute one step predictions p(j..Nb I X’) S(tlp (D,.,,,IX,) B. ADMISSIBILITY OF THE BLIND EQUALIZATION BY...NAVAL POSTGRADUATE SCHOOL Monterey, California •GR AD13 DTIC 94-07381 AR 0C199 THESIS S 0 LECTE4u KALMAN FILTERING APPROACH TO BLIND EQUALIZATION by...FILTERING APPROACH 5. FUNDING NUMBERS TO BLIND EQUALIZATION S. AUTHOR(S) Mehmet Kutlu 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) S

  18. Ancilla-driven universal blind quantum computation

    NASA Astrophysics Data System (ADS)

    Sueki, Takahiro; Koshiba, Takeshi; Morimae, Tomoyuki

    2013-06-01

    Blind quantum computation is a new quantum secure protocol, which enables Alice who does not have enough quantum technology to delegate her computation to Bob who has a fully fledged quantum power without revealing her input, output, and algorithm. So far, blind quantum computation has been considered only for the circuit model and the measurement-based model. Here we consider the possibility and the limitation of blind quantum computation in the ancilla-driven model, which is a hybrid of the circuit and the measurement-based models.

  19. Blindness of Johann Sebastian Bach.

    PubMed

    Tarkkanen, Ahti

    2013-03-01

    Johann Sebastian Bach (1685-1750) was one of the greatest composers of all time. Apart from performing as a brilliant organist, he composed over 1.100 works in almost every musical genre. He was known as a hardworking, deeply Christian person, who had to support his family of 20 children and many students staying at his home. At the age of 64 years, his vision started to decline. Old biographies claim that it was the result of overstressing his vision in poor illumination. By persuasion of his friends, he had his both eyes operated by a travelling British eye surgeon. A cataract couching was performed. After surgery, Bach was totally blind and unable to play an organ, compose or direct choirs and orchestras. He was confined to bed and suffering from immense pain of the eyes and the body. He died <4 months after surgery. In this paper, as the plausible diagnosis, intractable glaucoma because of pupillary block or secondary to phacoanaphylactic endophthalmitis is suggested.

  20. HIV/AIDS and blindness.

    PubMed Central

    Kestelyn, P. G.; Cunningham, E. T.

    2001-01-01

    Nearly 34 million people are currently living with HIV/AIDS: ocular complications are common, affecting 50% to 75% of all such patients at some point during the course of their illness. Cytomegalovirus retinitis is by far the most frequent cause of vision loss in patients with AIDS. Although the prevalence of cytomegalovirus retinitis is decreasing in industrialized countries because of the widespread availability of highly active antiretroviral therapy, between 10% and 20% of HIV-infected patients worldwide can be expected to lose vision in one or both eyes as a result of ocular cytomegalovirus infection. Less frequent but important causes of bilateral vision loss in patients with HIV/AIDS include varicella zoster virus and herpes simplex virus retinitis, HIV-related ischaemic microvasculopathy, ocular syphilis, ocular tuberculosis, cryptococcal meningitis, and ocular toxic or allergic drug reactions. At present, most patients with HIV/AIDS in developing countries who lose their vision have a very limited life expectancy. As antiretroviral therapy makes its way to these countries, however, both life expectancy and the prevalence of blindness related to HIV/AIDS can be expected to increase dramatically. PMID:11285664

  1. Blind estimation of reverberation time

    NASA Astrophysics Data System (ADS)

    Ratnam, Rama; Jones, Douglas L.; Wheeler, Bruce C.; O'Brien, William D.; Lansing, Charissa R.; Feng, Albert S.

    2003-11-01

    The reverberation time (RT) is an important parameter for characterizing the quality of an auditory space. Sounds in reverberant environments are subject to coloration. This affects speech intelligibility and sound localization. Many state-of-the-art audio signal processing algorithms, for example in hearing-aids and telephony, are expected to have the ability to characterize the listening environment, and turn on an appropriate processing strategy accordingly. Thus, a method for characterization of room RT based on passively received microphone signals represents an important enabling technology. Current RT estimators, such as Schroeder's method, depend on a controlled sound source, and thus cannot produce an online, blind RT estimate. Here, a method for estimating RT without prior knowledge of sound sources or room geometry is presented. The diffusive tail of reverberation was modeled as an exponentially damped Gaussian white noise process. The time-constant of the decay, which provided a measure of the RT, was estimated using a maximum-likelihood procedure. The estimates were obtained continuously, and an order-statistics filter was used to extract the most likely RT from the accumulated estimates. The procedure was illustrated for connected speech. Results obtained for simulated and real room data are in good agreement with the real RT values.

  2. Psychosocial implications of blindness and low vision in students of a school for children with blindness

    PubMed Central

    Ishtiaq, Rizwan; Chaudhary, Muhammad Hamid; Rana, Muhammad Atif; Jamil, Abdur Rehman

    2016-01-01

    Objective: To find out the psychosocial implications of blindness and low vision in students of blind school Bahawalpur. Methods: A cross sectional descriptive study was carried out in Higher Secondary School for blind, Bahawalpur after getting approval from Institutional review board of Quaid-e-Azam Medical College, Bahawalpur and Principal of Blind School, Bahawalpur. Forty willing students filled a customized questionnaire, consisting of questions about logistic variables and questions regarding areas of satisfaction. Statistical analysis was performed using SPSS version 18. Results: Out of 40, 55% (22/40) of them were found depressed (as assessed through DSM-lV), 50% (20/40) were having difficulty in making new contact but 52.5% (21/40) were satisfied with family care. Conclusion: Sixty percent (24/40) of blind school children experienced difficulty in their life. This study showed that blindness or low vision does have psychological implications like feeling of guilt, anxiety, sadness & depression. PMID:27182255

  3. Universal blind quantum computation for hybrid system

    NASA Astrophysics Data System (ADS)

    Huang, He-Liang; Bao, Wan-Su; Li, Tan; Li, Feng-Guang; Fu, Xiang-Qun; Zhang, Shuo; Zhang, Hai-Long; Wang, Xiang

    2017-08-01

    As progress on the development of building quantum computer continues to advance, first-generation practical quantum computers will be available for ordinary users in the cloud style similar to IBM's Quantum Experience nowadays. Clients can remotely access the quantum servers using some simple devices. In such a situation, it is of prime importance to keep the security of the client's information. Blind quantum computation protocols enable a client with limited quantum technology to delegate her quantum computation to a quantum server without leaking any privacy. To date, blind quantum computation has been considered only for an individual quantum system. However, practical universal quantum computer is likely to be a hybrid system. Here, we take the first step to construct a framework of blind quantum computation for the hybrid system, which provides a more feasible way for scalable blind quantum computation.

  4. 33 CFR 117.861 - Blind Slough.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OPERATION REGULATIONS Specific Requirements Oregon § 117.861 Blind Slough. The draws of the Portland and... of Fisheries and the Fish Commission of Oregon) for the Columbia River Fishery below Bonneville Dam....

  5. 33 CFR 117.861 - Blind Slough.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OPERATION REGULATIONS Specific Requirements Oregon § 117.861 Blind Slough. The draws of the Portland and... of Fisheries and the Fish Commission of Oregon) for the Columbia River Fishery below Bonneville Dam....

  6. 33 CFR 117.861 - Blind Slough.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OPERATION REGULATIONS Specific Requirements Oregon § 117.861 Blind Slough. The draws of the Portland and... of Fisheries and the Fish Commission of Oregon) for the Columbia River Fishery below Bonneville Dam....

  7. 33 CFR 117.861 - Blind Slough.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OPERATION REGULATIONS Specific Requirements Oregon § 117.861 Blind Slough. The draws of the Portland and... of Fisheries and the Fish Commission of Oregon) for the Columbia River Fishery below Bonneville Dam....

  8. 33 CFR 117.861 - Blind Slough.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OPERATION REGULATIONS Specific Requirements Oregon § 117.861 Blind Slough. The draws of the Portland and... of Fisheries and the Fish Commission of Oregon) for the Columbia River Fishery below Bonneville Dam....

  9. Teaching Introductory Statistics to Blind Students

    ERIC Educational Resources Information Center

    Marson, Stephen M.; Harrington, Charles F.; Walls, Adam

    2013-01-01

    The challenges of learning statistics, particularly distributions and their characteristics, can be potentially monumental for vision impaired and blind students. The authors provide some practical advice for teaching these students.

  10. Imagery limitations in totally congenitally blind subjects.

    PubMed

    De Beni, R; Cornoldi, C

    1988-10-01

    Research on totally blind subjects performing tasks that involve visual imagery has often shown that they do not behave differently from matched sighted subjects, even when their blindness is congenital. If visual imagery is based on visual perception, such tasks may not required visual imagery. In the present article visual images are considered as representations maintaining some properties of visible objects and constructed on the basis of information from various sources. Owing to the absence of visual experience, the limitations of such representations are explored in a series of experiments requiring memorization of single nouns, pairs of nouns, or triplets of nouns associated with a cue noun. Recall by blind subjects was impaired when multiple interactive images (with noun pairs and triplets) are formed. The poorer recall of blind subjects reflected also loss of order information. Recall was better for both groups with locative noun cues and high-imagery targets.

  11. Teaching Introductory Statistics to Blind Students

    ERIC Educational Resources Information Center

    Marson, Stephen M.; Harrington, Charles F.; Walls, Adam

    2013-01-01

    The challenges of learning statistics, particularly distributions and their characteristics, can be potentially monumental for vision impaired and blind students. The authors provide some practical advice for teaching these students.

  12. Libraries, Blind People, and the IYDP.

    ERIC Educational Resources Information Center

    Thiele, Paul L.

    1982-01-01

    The article links the roles of libraries and professional library staffs to the newly emerging consciousness of the "library rights" of blind and print handicapped persons throughout the world. (Author)

  13. The neural substrates associated with inattentional blindness.

    PubMed

    Thakral, Preston P

    2011-12-01

    Inattentional blindness is the failure to perceive salient stimuli presented at unattended locations. Whereas the behavioral manifestation of inattentional blindness has been investigated, the neural basis of this phenomenon has remained elusive. In the current study, event-related fMRI was used to identify the neural substrates associated with inattentional blindness. During central fixation, participants named colored digits presented at a peripheral location. On a subset of trials, an unexpected checkerboard circle (the critical stimulus) was presented at the same eccentricity along with the colored digits (a post-scan questionnaire assessed participants' awareness of the critical stimulus). Neural activity during inattentional blindness was observed in the prefrontal cortex. Together with previous findings, these results call into question the widespread view that activity in the prefrontal cortex reflects conscious processing. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. The Blind, From Braille to the Present.

    ERIC Educational Resources Information Center

    Truquet, Monique

    1980-01-01

    Traces the historical development of processing information for the blind from the system devised by Barbier to present systems of producing Braille documents using computers. Cites the impact of microprocessors and outlines possibilities for Braille reproductions in the future. (GS)

  15. Hypertension and color blindness in young men.

    PubMed

    Morton, W E

    1975-05-01

    Medical data from Selective Service registrants born from 1939 to 1941 were studied in Oregon and Colorado. Among 29,119 registrants with medical information (41.3% of all registrants), 1,073 (3.6%) had definite hypertension, and 1,226 (4.2%) had some type of color blindness. In both states, there was a highly significant association between the prevalence of hypertension and the prevalence of color blindness. Thus, definite hypertension was present in 6.0% of color clind individuals but in only 3.6% of those with unimparied color vision, while color blindness occurred in 6.8% with definite hypertension, in 5.8% with borderline hypertension, and in only 4.0% with normal blood pressure. The data did not differentiate among types of color blindness, and the reason for the association is not yet evident.

  16. Iterated Gate Teleportation and Blind Quantum Computation.

    PubMed

    Pérez-Delgado, Carlos A; Fitzsimons, Joseph F

    2015-06-05

    Blind quantum computation allows a user to delegate a computation to an untrusted server while keeping the computation hidden. A number of recent works have sought to establish bounds on the communication requirements necessary to implement blind computation, and a bound based on the no-programming theorem of Nielsen and Chuang has emerged as a natural limiting factor. Here we show that this constraint only holds in limited scenarios, and show how to overcome it using a novel method of iterated gate teleportations. This technique enables drastic reductions in the communication required for distributed quantum protocols, extending beyond the blind computation setting. Applied to blind quantum computation, this technique offers significant efficiency improvements, and in some scenarios offers an exponential reduction in communication requirements.

  17. Iterated Gate Teleportation and Blind Quantum Computation

    NASA Astrophysics Data System (ADS)

    Pérez-Delgado, Carlos A.; Fitzsimons, Joseph F.

    2015-06-01

    Blind quantum computation allows a user to delegate a computation to an untrusted server while keeping the computation hidden. A number of recent works have sought to establish bounds on the communication requirements necessary to implement blind computation, and a bound based on the no-programming theorem of Nielsen and Chuang has emerged as a natural limiting factor. Here we show that this constraint only holds in limited scenarios, and show how to overcome it using a novel method of iterated gate teleportations. This technique enables drastic reductions in the communication required for distributed quantum protocols, extending beyond the blind computation setting. Applied to blind quantum computation, this technique offers significant efficiency improvements, and in some scenarios offers an exponential reduction in communication requirements.

  18. Florida's Industrial Training Laboratory for Blind Persons

    ERIC Educational Resources Information Center

    Hoskins, Len

    1974-01-01

    Described is the 6-month program of the Industrial Training Laboratory (Florida) that has graduated 50 blind persons in 5 years and has enabled 48 of the graduates to hold full-time competitive jobs. (Author/MC)

  19. Embodiment awareness, mathematics discourse, and the blind.

    PubMed

    Quek, Francis; McNeill, David

    2006-12-01

    Blindness might be described as a biological condition, and thus remedies could be in the realm of biotechnology. However, the convergence of information technology and cognitive science offers great opportunities for understanding and helping blind children as they learn mathematics, the crosscutting discipline most important for all branches of science and engineering. This article outlines our logic and approach for providing blind students with awareness of the embodiment of their teachers to maintain situated communication. First, we shall show that math discourse is inherently spatiotemporal, and that this information is carried by gesticulation in conjunction with speech. Second, we shall explore the capacity of those who are blind for the imagism necessary for mathematics reasoning. Third, we shall advance a set of augmentative devices suggested by our analysis. Finally, we shall outline our ongoing experiments to validate our rationale.

  20. Fear of blindness and perceptions about blind people. The Andhra Pradesh Eye Disease Study.

    PubMed

    Giridhar, Pyda; Dandona, Rakhi; Prasad, Mudigonda N; Kovai, Vilas; Dandona, Lalit

    2002-09-01

    This study assessed the fear of being affected by illness and disability including blindness, and perceptions of the population towards blind people in the Indian state of Andhra Pradesh. A total of 11,786 subjects of all ages were sampled from 94 clusters in one urban and three rural study areas of Andhra Pradesh using stratified, random, cluster, systematic sampling to represent the population of this state. A total of 10,293 subjects of all ages underwent a detailed interview and dilated ocular evaluation. Subjects > 15 years of age (7,432) were interviewed regarding fear of illness/disability and their perceptions of blind people. The fear of blindness was assessed in comparison to cancer, severe mental illness, heart attack, losing limbs, deafness, inability to speak, and paralysis. A majority of the study population feared all the illnesses and disabilities assessed. The prevalence of fear of blindness was 90.9% (95% confidence interval 89.1-92.8%) and 92.1% (95% confidence interval 90.6-93.6%) in urban and rural study areas respectively. With multiple logistic regression the fear of blindness was significantly higher for those with any level of education and for those living in the rural study areas. The proportion of those having positive feelings towards blind people was higher in the urban study area. A high prevalence of blindness, 1.84%, has been reported in this population previously. These data suggest that this population feared blindness, and yet there is a high rate of blindness. This reflects the need for increasing awareness about blindness in this population through eye health promotion strategies in order to reduce blindness, and awareness regarding the availability of rehabilitation services.

  1. Shape Perception and Navigation in Blind Adults

    PubMed Central

    Gori, Monica; Cappagli, Giulia; Baud-Bovy, Gabriel; Finocchietti, Sara

    2017-01-01

    Different sensory systems interact to generate a representation of space and to navigate. Vision plays a critical role in the representation of space development. During navigation, vision is integrated with auditory and mobility cues. In blind individuals, visual experience is not available and navigation therefore lacks this important sensory signal. In blind individuals, compensatory mechanisms can be adopted to improve spatial and navigation skills. On the other hand, the limitations of these compensatory mechanisms are not completely clear. Both enhanced and impaired reliance on auditory cues in blind individuals have been reported. Here, we develop a new paradigm to test both auditory perception and navigation skills in blind and sighted individuals and to investigate the effect that visual experience has on the ability to reproduce simple and complex paths. During the navigation task, early blind, late blind and sighted individuals were required first to listen to an audio shape and then to recognize and reproduce it by walking. After each audio shape was presented, a static sound was played and the participants were asked to reach it. Movements were recorded with a motion tracking system. Our results show three main impairments specific to early blind individuals. The first is the tendency to compress the shapes reproduced during navigation. The second is the difficulty to recognize complex audio stimuli, and finally, the third is the difficulty in reproducing the desired shape: early blind participants occasionally reported perceiving a square but they actually reproduced a circle during the navigation task. We discuss these results in terms of compromised spatial reference frames due to lack of visual input during the early period of development. PMID:28144226

  2. [Temporary blindness after transnasal ethmoidectomy (author's transl)].

    PubMed

    Langnickel, R

    1978-05-01

    A unilateral blindness after transnasal ethmoidectomy was diagnosed postoperatively while the patient was still in theatre. Exploration via an external approach was performed immediately, a haematoma was drained and the posteroir ethmoid artery was cauterized. This led to a recovery of vision. The temporary blindness was probably due to increased intraorbital pressure by the retrobulbar haematoma which led to stretching of and pressure on the optic nerve.

  3. Blindness in a bladder cancer patient.

    PubMed

    Remón, J; Guardeño, R; Badía, A; Cardona, T; Picaza, J M; Lianes, P

    2007-02-01

    Blindness is an unusual symptom in the clinical course of cancer. When it appears it is necessary to differentiate between benign and malign causes. Brain metastases in bladder cancer are extremely rare. MRI is the best diagnostic option. We present a deaf-and-dumb male with subacute blindness, 12 months after the diagnosis of a metastatic bladder cancer. Computerised tomography scan and MRI revealed a mass into the pituitary gland and sella, probably of metastatic origin.

  4. Prevention of Blindness in the USSR.

    ERIC Educational Resources Information Center

    Trutneva, K.

    The booklet describes approaches used in the Union of Soviet Socialist Republics to prevent blindness. It contrasts conditions prior to 1917 (300 eye doctors mainly located in large cities and 2,000 hospital beds for the 300,000 totally blind and 7,000,000 people with trachoma) with conditions in 1971 when in the Ukraine alone there were 3,000 eye…

  5. Astronomy for the Blind and Visually Impaired

    NASA Astrophysics Data System (ADS)

    Kraus, S.

    2016-12-01

    This article presents a number of ways of communicating astronomy topics, ranging from classical astronomy to modern astrophysics, to the blind and visually impaired. A major aim of these projects is to provide access which goes beyond the use of the tactile sense to improve knowledge transfer for blind and visually impaired students. The models presented here are especially suitable for young people of secondary school age.

  6. Shape Perception and Navigation in Blind Adults.

    PubMed

    Gori, Monica; Cappagli, Giulia; Baud-Bovy, Gabriel; Finocchietti, Sara

    2017-01-01

    Different sensory systems interact to generate a representation of space and to navigate. Vision plays a critical role in the representation of space development. During navigation, vision is integrated with auditory and mobility cues. In blind individuals, visual experience is not available and navigation therefore lacks this important sensory signal. In blind individuals, compensatory mechanisms can be adopted to improve spatial and navigation skills. On the other hand, the limitations of these compensatory mechanisms are not completely clear. Both enhanced and impaired reliance on auditory cues in blind individuals have been reported. Here, we develop a new paradigm to test both auditory perception and navigation skills in blind and sighted individuals and to investigate the effect that visual experience has on the ability to reproduce simple and complex paths. During the navigation task, early blind, late blind and sighted individuals were required first to listen to an audio shape and then to recognize and reproduce it by walking. After each audio shape was presented, a static sound was played and the participants were asked to reach it. Movements were recorded with a motion tracking system. Our results show three main impairments specific to early blind individuals. The first is the tendency to compress the shapes reproduced during navigation. The second is the difficulty to recognize complex audio stimuli, and finally, the third is the difficulty in reproducing the desired shape: early blind participants occasionally reported perceiving a square but they actually reproduced a circle during the navigation task. We discuss these results in terms of compromised spatial reference frames due to lack of visual input during the early period of development.

  7. From Perception to Metacognition: Auditory and Olfactory Functions in Early Blind, Late Blind, and Sighted Individuals

    PubMed Central

    Cornell Kärnekull, Stina; Arshamian, Artin; Nilsson, Mats E.; Larsson, Maria

    2016-01-01

    Although evidence is mixed, studies have shown that blind individuals perform better than sighted at specific auditory, tactile, and chemosensory tasks. However, few studies have assessed blind and sighted individuals across different sensory modalities in the same study. We tested early blind (n = 15), late blind (n = 15), and sighted (n = 30) participants with analogous olfactory and auditory tests in absolute threshold, discrimination, identification, episodic recognition, and metacognitive ability. Although the multivariate analysis of variance (MANOVA) showed no overall effect of blindness and no interaction with modality, follow-up between-group contrasts indicated a blind-over-sighted advantage in auditory episodic recognition, that was most pronounced in early blind individuals. In contrast to the auditory modality, there was no empirical support for compensatory effects in any of the olfactory tasks. There was no conclusive evidence for group differences in metacognitive ability to predict episodic recognition performance. Taken together, the results showed no evidence of an overall superior performance in blind relative sighted individuals across olfactory and auditory functions, although early blind individuals exceled in episodic auditory recognition memory. This observation may be related to an experience-induced increase in auditory attentional capacity. PMID:27729884

  8. Causes of blindness in children in the blind schools of Ethiopia.

    PubMed

    Wolde-Gebriel, Z; Gebru, H; West, C E

    1992-01-01

    A total of 721 children in the six schools for the blind in Ethiopia were studied. In 1988-1989 histories were taken to ascertain the predisposing factors and ophthalmological examinations and records were used to determine the causes of blindness. Ninety-five per cent of those examined had bilateral blindness, 12% did not know how they had become blind and, of those who provided information on how they became blind, 21% knew that they were born blind, 30% implicated measles as being responsible, and 13% implicated 'mitch' which is an Amharic term used to describe a very wide range of nonspecific and vague illnesses of which measles probably constitutes a significant proportion. Seventy per cent of the blindness was due to either corneal opacity or phthisis bulbi. Of those with non-congenital bilateral corneal opacity or phthisis bulbi, 40% were preceded by measles and 17% by mitch. A study of 66 adults in the handicraft and skill-training centres attached to the blind schools indicated that the principal predisposing factors of blindness were mitch (30%), smallpox (15%), cataract (12%), and traditional eye medicine (11%). Seventy percent had corneal scars of phthisis bulbi and 14% cataract.

  9. Prevalence of colour blindness in young Jordanians.

    PubMed

    Al-Aqtum, M T; Al-Qawasmeh, M H

    2001-01-01

    Colour blindness is one of the common genetic disorders observed in all human populations. It is a sex-linked recessive trait. The genes are located on the X chromosome within the Xq28 band. 1,418 university students (1,200 female and 218 male) from Zarka Private University and the Hashemite University were randomly selected and tested for congenital red/green colour blindness, by using Ishihara pseudo-isochromatic colour plates. A total of 23 individuals were found to be colour blind. In females, 4 students (0.33%) were colour blind: 1 of them showed protanomalia, 1 protanopia and 2 deuteranomalia. In males, 19 students (8.72%) were colour blind: 4 showed protanomalia, 3 protanopia, 8 deuteranomalia and 4 deuteranopia. The allelic frequencies of the colour vision gene were found to be 0.087 in males, 0.003 in females and 0.016 in the total population. Studies on colour blindness in Jordan are very few; this population-based investigation is meant to fill a gap in this field.

  10. Prevalence and causes of corneal blindness.

    PubMed

    Wang, Haijing; Zhang, Yaoguang; Li, Zhijian; Wang, Tiebin; Liu, Ping

    2014-04-01

    The study aimed to assess the prevalence and causes of corneal blindness in a rural northern Chinese population. Cross-sectional study. The cluster random sampling method was used to select the sample. This population-based study included 11 787 participants of all ages in rural Heilongjiang Province, China. These participants underwent a detailed interview and eye examination that included the measurement of visual acuity, slit-lamp biomicroscopy and direct ophthalmoscopy. An eye was considered to have corneal blindness if the visual acuity was <9/18 because of corneal diseases. The main outcome measure was prevalence rates of corneal blindness and low vision. Among the 10 384 people enrolled in the study, the prevalence of corneal blindness is 0.3% (95% confidence interval 0.2-0.4%). The leading cause was keratitis in childhood (40.0%), followed by ocular trauma (33.3%) and keratitis in adulthood (20.0%). Age and illiteracy were found to be associated with an increased prevalence of corneal blindness. Blindness because of corneal diseases in rural areas of Northern China is a significant public health problem that needs to be given more attention. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

  11. Unblinding the dark matter blind spots

    DOE PAGES

    Han, Tao; Kling, Felix; Su, Shufang; ...

    2017-02-10

    The dark matter (DM) blind spots in the Minimal Supersymmetric Standard Model (MSSM) refer to the parameter regions where the couplings of the DM particles to the $Z$-boson or the Higgs boson are almost zero, leading to vanishingly small signals for the DM direct detections. In this paper, we carry out comprehensive analyses for the DM searches under the blind-spot scenarios in MSSM. Guided by the requirement of acceptable DM relic abundance, we explore the complementary coverage for the theory parameters at the LHC, the projection for the future underground DM direct searches, and the indirect searches from the relicmore » DM annihilation into photons and neutrinos. We find that (i) the spin-independent (SI) blind spots may be rescued by the spin-dependent (SD) direct detection in the future underground experiments, and possibly by the indirect DM detections from IceCube and SuperK neutrino experiments; (ii) the detection of gamma rays from Fermi-LAT may not reach the desirable sensitivity for searching for the DM blind-spot regions; (iii) the SUSY searches at the LHC will substantially extend the discovery region for the blind-spot parameters. As a result, the dark matter blind spots thus may be unblinded with the collective efforts in future DM searches.« less

  12. Unblinding the dark matter blind spots

    NASA Astrophysics Data System (ADS)

    Han, Tao; Kling, Felix; Su, Shufang; Wu, Yongcheng

    2017-02-01

    The dark matter (DM) blind spots in the Minimal Supersymmetric Standard Model (MSSM) refer to the parameter regions where the couplings of the DM particles to the Z-boson or the Higgs boson are almost zero, leading to vanishingly small signals for the DM direct detections. In this paper, we carry out comprehensive analyses for the DM searches under the blind-spot scenarios in MSSM. Guided by the requirement of acceptable DM relic abundance, we explore the complementary coverage for the theory parameters at the LHC, the projection for the future underground DM direct searches, and the indirect searches from the relic DM annihilation into photons and neutrinos. We find that (i) the spin-independent (SI) blind spots may be rescued by the spin-dependent (SD) direct detection in the future underground experiments, and possibly by the indirect DM detections from IceCube and SuperK neutrino experiments; (ii) the detection of gamma rays from Fermi-LAT may not reach the desirable sensitivity for searching for the DM blind-spot regions; (iii) the SUSY searches at the LHC will substantially extend the discovery region for the blind-spot parameters. The dark matter blind spots thus may be unblinded with the collective efforts in future DM searches.

  13. Reduced taste sensitivity in congenital blindness.

    PubMed

    Gagnon, Lea; Kupers, Ron; Ptito, Maurice

    2013-07-01

    Sight is undoubtedly not only important for food identification and selection but also for the modulation of gustatory sensitivity. We can, therefore, assume that taste sensitivity and eating habits are affected by visual deprivation from birth. We measured taste detection and identification thresholds of the 5 basic tastants in 13 congenitally blind and 13 sighted control subjects. Participants also answered several eating habits questionnaires, including the Food Neophobia Scale, the Food Variety Seeking Tendency Scale, the Intuitive Eating Scale, and the Body Awareness Questionnaire. Our behavioral results showed that compared with the normal sighted, blind subjects have increased thresholds for taste detection and taste identification. This finding is at odds with the superior performance of congenitally blind subjects in several tactile, auditory and olfactory tasks. Our psychometric data further indicate that blind subjects more strongly rely on internal hunger and satiety cues, instead of external contextual or emotional cues, to decide when and what to eat. We suggest that the lower taste sensitivity observed in congenitally blind individuals is due to various blindness-related obstacles when shopping for food, cooking and eating out, all of which contribute to underexpose the gustatory system to a larger variety of taste stimuli.

  14. Auditory gap detection in the early blind.

    PubMed

    Weaver, Kurt E; Stevens, Alexander A

    2006-01-01

    For blind individuals, audition provides critical information for interacting with the environment. Individuals blinded early in life (EB) typically show enhanced auditory abilities relative to sighted controls as measured by tasks requiring complex discrimination, attention and memory. In contrast, few deficits have been reported on tasks involving auditory sensory thresholds (e.g., Yates, J.T., Johnson, R.M., Starz, W.J., 1972. Loudness perception of the blind. Audiology 11(5), 368-376; Starlinger, I., Niemeyer, W., 1981. Do the blind hear better? Investigations on auditory processing in congenital or early acquired blindness. I. Peripheral functions. Audiology 20(6), 503-509). A study of gap detection stands at odds with this distinction [Muchnik, C., Efrati, M., Nemeth, E., Malin, M., Hildesheimer, M., 1991. Central auditory skills in blind and sighted subjects. Scand. Audiol. 20(1), 19-23]. In the current investigation we re-examined gap detection abilities in the EB using a single-interval, yes/no method. A group of younger sighted control individuals (SCy) was included in the analysis in addition to EB and sighted age matched control individuals (SCm) in order to examine the effect of age on gap detection performance. Estimates of gap detection thresholds for EB subjects were nearly identical to SCm subjects and slightly poorer relative to the SCy subjects. These results suggest some limits on the extent of auditory temporal advantages in the EB.

  15. 42 CFR 435.530 - Definition of blindness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Definition of blindness. 435.530 Section 435.530... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.530 Definition of blindness. (a) Definition. The agency must use the same definition of blindness as used under SSI, except...

  16. 42 CFR 436.530 - Definition of blindness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Definition of blindness. 436.530 Section 436.530... Requirements for Medicaid Eligibility Blindness § 436.530 Definition of blindness. (a) Definition. The agency must use the definition of blindness that is used in the State plan for AB or AABD. (b) State plan...

  17. 42 CFR 436.530 - Definition of blindness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Definition of blindness. 436.530 Section 436.530... Requirements for Medicaid Eligibility Blindness § 436.530 Definition of blindness. (a) Definition. The agency must use the definition of blindness that is used in the State plan for AB or AABD. (b) State plan...

  18. 42 CFR 436.530 - Definition of blindness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Definition of blindness. 436.530 Section 436.530... Requirements for Medicaid Eligibility Blindness § 436.530 Definition of blindness. (a) Definition. The agency must use the definition of blindness that is used in the State plan for AB or AABD. (b) State plan...

  19. 42 CFR 435.530 - Definition of blindness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Definition of blindness. 435.530 Section 435.530... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.530 Definition of blindness. (a) Definition. The agency must use the same definition of blindness as used under SSI, except...

  20. 42 CFR 435.530 - Definition of blindness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Definition of blindness. 435.530 Section 435.530... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.530 Definition of blindness. (a) Definition. The agency must use the same definition of blindness as used under SSI, except...

  1. 42 CFR 435.530 - Definition of blindness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Definition of blindness. 435.530 Section 435.530... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.530 Definition of blindness. (a) Definition. The agency must use the same definition of blindness as used under SSI, except...

  2. 42 CFR 435.530 - Definition of blindness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Definition of blindness. 435.530 Section 435.530... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.530 Definition of blindness. (a) Definition. The agency must use the same definition of blindness as used under SSI, except...

  3. 42 CFR 436.530 - Definition of blindness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Definition of blindness. 436.530 Section 436.530... Requirements for Medicaid Eligibility Blindness § 436.530 Definition of blindness. (a) Definition. The agency must use the definition of blindness that is used in the State plan for AB or AABD. (b) State plan...

  4. 42 CFR 436.530 - Definition of blindness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Definition of blindness. 436.530 Section 436.530... Requirements for Medicaid Eligibility Blindness § 436.530 Definition of blindness. (a) Definition. The agency must use the definition of blindness that is used in the State plan for AB or AABD. (b) State plan...

  5. Multiply-Impaired Blind Children: A National Problem.

    ERIC Educational Resources Information Center

    Graham, Milton D.

    In 1966, a national survey reported on 8,887 multiply impaired (MI) blind children. About 56% were boys; 85% had been blind since before age 3, and half were totally blind. The principal causes of blindness were retrolental fibroplasia and congenital cataracts. Almost 63% had two or more additional disabilities (86.8% of those under age 6), such…

  6. Blind & Sighted Pioneer Teachers in 19th Century China & India.

    ERIC Educational Resources Information Center

    Miles, M.

    This paper discusses the education of people with blindness in China and India prior to the establishment of formal schools for the blind. Key people who advanced the education of people with blindness are highlighted, such as missionary teacher Mary Gutzlaff, who integrated Chinese orphan girls with blindness into her school at Macau. One of the…

  7. Programs for Deaf-Blind Children and Adults.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1995

    1995-01-01

    This report of the annual survey of programs for deaf-blind children and adults lists, by state, programs for deaf-blind children and youth, Helen Keller Centers for deaf-blind youth and adults, and programs for training teachers of deaf-blind students. Provided are program names, addresses, telephone numbers, and names of directors. (DB)

  8. Programs for Deaf-Blind Children and Adults.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 2000

    2000-01-01

    This annual directory lists programs for deaf-blind children and adults including programs for deaf-blind children and youth (national and state level), the Helen Keller Centers for deaf-blind youth and adults, and programs for training teachers of deaf-blind students. (DB)

  9. Changes in blindness prevalence over 16 years in Malawi: reduced prevalence but increased numbers of blind

    PubMed Central

    Courtright, P; Hoeshcmann, A; Metcalfe, N; Chirambo, M; Noertjojo, K; Barrows, J; Katz, J

    2003-01-01

    Background/aims: In the coming two decades significant increases in the burden of blindness are anticipated unless concerted efforts are made to improve eye care in developing countries. Evidence of changing prevalence rates or numbers of blind people are few. The change in blindness prevalence and the number of blind people in an adult population of Malawi was measured over a 16 year period. Methods: In 1999 a population based survey of blindness in adults (age 50+) was conducted in Chikwawa district of Malawi. Visual acuity and cause of vision loss were recorded for each eye independently. Blindness was defined as presenting better eye vision of <6/60. Findings from a 1983 survey of blindness in the same district (using similar methods) were re-analysed to be comparable with the survey conducted in 1999. Results: Among 1630 enumerated adults 89% were examined. The age adjusted prevalence of blindness in the adult population was 5.4% and more common in women than men. In each age group the prevalence of blindness was lower in 1999 than in 1983; the overall reduction in blindness was 31%. During this period the 50+ population in Malawi increased almost twofold. Extrapolating the Chikwawa district data to the Malawi population reveals that the number of blind people has increased by 24%; the increase is primarily because of the large increase in the size of the most elderly group, aged 70 and above. Conclusion: The majority of blind people in Chikwawa (1983 and 1999) are in the age group 70 and over. This group has had the largest proportional increase in population size in this time. Services in this population have improved in the intervening 16 years and yet there was still an increase in the number of blind people. There was little change in excess blindness in women, suggesting that the same barriers that prevented utilisation of services in 1983 probably persist in 1999. Efforts to reach the most elderly and to reach women are needed to lead to a reduction in

  10. 75 FR 47304 - Accessible Mobile Phone Options for People Who Are Blind, Deaf-Blind, or Have Low Vision

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ... COMMISSION Accessible Mobile Phone Options for People Who Are Blind, Deaf- Blind, or Have Low Vision AGENCY...-145, which shall be captioned ``Accessible Mobile Phone Options for People who are Blind, Deaf-blind... following issues: The wireless phone features and functions in the current marketplace that are not...

  11. Blind compressive sensing dynamic MRI

    PubMed Central

    Lingala, Sajan Goud; Jacob, Mathews

    2013-01-01

    We propose a novel blind compressive sensing (BCS) frame work to recover dynamic magnetic resonance images from undersampled measurements. This scheme models the dynamic signal as a sparse linear combination of temporal basis functions, chosen from a large dictionary. In contrast to classical compressed sensing, the BCS scheme simultaneously estimates the dictionary and the sparse coefficients from the undersampled measurements. Apart from the sparsity of the coefficients, the key difference of the BCS scheme with current low rank methods is the non-orthogonal nature of the dictionary basis functions. Since the number of degrees of freedom of the BCS model is smaller than that of the low-rank methods, it provides improved reconstructions at high acceleration rates. We formulate the reconstruction as a constrained optimization problem; the objective function is the linear combination of a data consistency term and sparsity promoting ℓ1 prior of the coefficients. The Frobenius norm dictionary constraint is used to avoid scale ambiguity. We introduce a simple and efficient majorize-minimize algorithm, which decouples the original criterion into three simpler sub problems. An alternating minimization strategy is used, where we cycle through the minimization of three simpler problems. This algorithm is seen to be considerably faster than approaches that alternates between sparse coding and dictionary estimation, as well as the extension of K-SVD dictionary learning scheme. The use of the ℓ1 penalty and Frobenius norm dictionary constraint enables the attenuation of insignificant basis functions compared to the ℓ0 norm and column norm constraint assumed in most dictionary learning algorithms; this is especially important since the number of basis functions that can be reliably estimated is restricted by the available measurements. We also observe that the proposed scheme is more robust to local minima compared to K-SVD method, which relies on greedy sparse coding

  12. Tactile Sensitivity and Braille Reading in People with Early Blindness and Late Blindness

    ERIC Educational Resources Information Center

    Oshima, Kensuke; Arai, Tetsuya; Ichihara, Shigeru; Nakano, Yasushi

    2014-01-01

    Introduction: The inability to read quickly can be a disadvantage throughout life. This study focused on the associations of braille reading fluency and individual factors, such as the age at onset of blindness and number of years reading braille, and the tactile sensitivity of people with early and late blindness. The relationship between reading…

  13. Our Blind Child: Bringing Up a Blind Child During Its Early Years.

    ERIC Educational Resources Information Center

    Pielasch, Helmut, Ed.; And Others

    The document contains 10 author contributed chapters (in four languages) which resulted from a 1976 international symposium on problems concerning the preschool education of blind children and the guidance of their parents. Chapters have the following titles (with authors and nationality in parentheses): "Development of the Blind Child"…

  14. Tactile Sensitivity and Braille Reading in People with Early Blindness and Late Blindness

    ERIC Educational Resources Information Center

    Oshima, Kensuke; Arai, Tetsuya; Ichihara, Shigeru; Nakano, Yasushi

    2014-01-01

    Introduction: The inability to read quickly can be a disadvantage throughout life. This study focused on the associations of braille reading fluency and individual factors, such as the age at onset of blindness and number of years reading braille, and the tactile sensitivity of people with early and late blindness. The relationship between reading…

  15. Our Blind Child: Bringing Up a Blind Child During Its Early Years.

    ERIC Educational Resources Information Center

    Pielasch, Helmut, Ed.; And Others

    The document contains 10 author contributed chapters (in four languages) which resulted from a 1976 international symposium on problems concerning the preschool education of blind children and the guidance of their parents. Chapters have the following titles (with authors and nationality in parentheses): "Development of the Blind Child"…

  16. Turning the tide of corneal blindness

    PubMed Central

    Oliva, Matthew S; Schottman, Tim; Gulati, Manoj

    2012-01-01

    Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world's largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind. PMID:22944753

  17. Blind topological measurement-based quantum computation.

    PubMed

    Morimae, Tomoyuki; Fujii, Keisuke

    2012-01-01

    Blind quantum computation is a novel secure quantum-computing protocol that enables Alice, who does not have sufficient quantum technology at her disposal, to delegate her quantum computation to Bob, who has a fully fledged quantum computer, in such a way that Bob cannot learn anything about Alice's input, output and algorithm. A recent proof-of-principle experiment demonstrating blind quantum computation in an optical system has raised new challenges regarding the scalability of blind quantum computation in realistic noisy conditions. Here we show that fault-tolerant blind quantum computation is possible in a topologically protected manner using the Raussendorf-Harrington-Goyal scheme. The error threshold of our scheme is 4.3 × 10(-3), which is comparable to that (7.5 × 10(-3)) of non-blind topological quantum computation. As the error per gate of the order 10(-3) was already achieved in some experimental systems, our result implies that secure cloud quantum computation is within reach.

  18. Blind guidance system based on laser triangulation

    NASA Astrophysics Data System (ADS)

    Wu, Jih-Huah; Wang, Jinner-Der; Fang, Wei; Lee, Yun-Parn; Shan, Yi-Chia; Kao, Hai-Ko; Ma, Shih-Hsin; Jiang, Joe-Air

    2012-05-01

    We propose a new guidance system for the blind. An optical triangulation method is used in the system. The main components of the proposed system comprise of a notebook computer, a camera, and two laser modules. The track image of the light beam on the ground or on the object is captured by the camera and then the image is sent to the notebook computer for further processing and analysis. Using a developed signal-processing algorithm, our system can determine the object width and the distance between the object and the blind person through the calculation of the light line positions on the image. A series of feasibility tests of the developed blind guidance system were conducted. The experimental results show that the distance between the test object and the blind can be measured with a standard deviation of less than 8.5% within the range of 40 and 130 cm, while the test object width can be measured with a standard deviation of less than 4.5% within the range of 40 and 130 cm. The application potential of the designed system to the blind guidance can be expected.

  19. Auditory motion processing after early blindness

    PubMed Central

    Jiang, Fang; Stecker, G. Christopher; Fine, Ione

    2014-01-01

    Studies showing that occipital cortex responds to auditory and tactile stimuli after early blindness are often interpreted as demonstrating that early blind subjects “see” auditory and tactile stimuli. However, it is not clear whether these occipital responses directly mediate the perception of auditory/tactile stimuli, or simply modulate or augment responses within other sensory areas. We used fMRI pattern classification to categorize the perceived direction of motion for both coherent and ambiguous auditory motion stimuli. In sighted individuals, perceived motion direction was accurately categorized based on neural responses within the planum temporale (PT) and right lateral occipital cortex (LOC). Within early blind individuals, auditory motion decisions for both stimuli were successfully categorized from responses within the human middle temporal complex (hMT+), but not the PT or right LOC. These findings suggest that early blind responses within hMT+ are associated with the perception of auditory motion, and that these responses in hMT+ may usurp some of the functions of nondeprived PT. Thus, our results provide further evidence that blind individuals do indeed “see” auditory motion. PMID:25378368

  20. Turning the tide of corneal blindness.

    PubMed

    Oliva, Matthew S; Schottman, Tim; Gulati, Manoj

    2012-01-01

    Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world's largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind.

  1. Vibrotactile Guidance for Wayfinding of Blind Walkers.

    PubMed

    Flores, German; Kurniawan, Sri; Manduchi, Roberto; Martinson, Eric; Morales, Lourdes M; Sisbot, Emrah Akin

    2015-01-01

    We propose a vibrotactile interface in the form of a belt for guiding blind walkers. This interface enables blind walkers to receive haptic directional instructions along complex paths without negatively impacting users' ability to listen and/or perceive the environment the way some auditory directional instructions do. The belt interface was evaluated in a controlled study with 10 blind individuals and compared to the audio guidance. The experiments were videotaped and the participants' behaviors and comments were content analyzed. Completion times and deviations from ideal paths were also collected and statistically analyzed. By triangulating the quantitative and qualitative data, we found that the belt resulted in closer path following to the expense of speed. In general, the participants were positive about the use of vibrotactile belt to provide directional guidance.

  2. Patient-physician communication when blindness threatens.

    PubMed

    Hopper, S V; Fischbach, R L

    1989-08-01

    The threat of blindness creates a difficult and challenging environment for communication between patients and their ophthalmologists. This study examined concordance between what patients want to know from their physicians about their eye condition and what physicians believe their patients need to know. Eight retinal specialists and 24 of their patients with proliferative diabetic retinopathy and at risk of blindness were interviewed using parallel-constructed instruments. Although all recognized that blindness was the patients' greatest concern, disparities were noted that involved the desire/need to know about the possibility of vision loss, the causes of the eye condition, the results of each eye exam, and the extent of patient confusion. Physicians, while conscientious about informed consent, described various communication behaviors to avoid discussing bad news.

  3. Brief mindfulness induction reduces inattentional blindness.

    PubMed

    Schofield, Timothy P; Creswell, J David; Denson, Thomas F

    2015-12-01

    Prior research has linked mindfulness to improvements in attention, and suggested that the effects of mindfulness are particularly pronounced when individuals are cognitively depleted or stressed. Yet, no studies have tested whether mindfulness improves declarative awareness of unexpected stimuli in goal-directed tasks. Participants (N=794) were either depleted (or not) and subsequently underwent a brief mindfulness induction (or not). They then completed an inattentional blindness task during which an unexpected distractor appeared on the computer monitor. This task was used to assess declarative conscious awareness of the unexpected distractor's presence and the extent to which its perceptual properties were encoded. Mindfulness increased awareness of the unexpected distractor (i.e., reduced rates of inattentional blindness). Contrary to predictions, no mindfulness×depletion interaction emerged. Depletion however, increased perceptual encoding of the distractor. These results suggest that mindfulness may foster awareness of unexpected stimuli (i.e., reduce inattentional blindness). Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Blinding trachoma: prevention with the safe strategy.

    PubMed

    West, Sheila K

    2003-11-01

    Trachoma, the second leading cause of blindness worldwide, differentially affects the poorest communities, which may have the least access to resources. With the establishment of the Global Elimination of Blinding Trachoma by 2020 (GET 2020) goal, the World Health Organization has set an ambitious target for country programs. The currently recommended surgery for trichiasis/entropion, antibiotics for active disease, facial cleanliness, and environmental change to reduce transmission (SAFE) strategy targets all key elements believed to be necessary for a short- and long-term intervention program. This report reviews the need for a multi-faceted strategy, and the evidence supporting the elements of SAFE. Concerns about the implementation are discussed. Additional research is suggested that will enhance the implementation of the SAFE strategy. In the current climate of significant political and social momentum for trachoma control, the SAFE strategy is a safe bet to accomplish the elimination of blinding trachoma.

  5. A Novel Quantum Proxy Blind Signature Scheme

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Xie, Shu-Cui; Zhang, Jian-Zhong

    2017-05-01

    A novel quantum proxy blind signature scheme is proposed. In this scheme, a special type of non-maximally entangled three-qubit state is introduced as a quantum channel, which can realize perfect teleportation. The message sender U blinds his message by means of preparing two groups of non-orthogonal single-photon states. According to the original signer Charlie's delegation message, the proxy signer Alice generates a corresponding signature. The arbitrator Trent can help the receiver Bob verify the signature, and also prevent Bob from doing any damage. The above-mentioned advantages make this scheme different from some existing schemes. It is showed that our scheme has the properties of undeniability, unforgeability, blindness, untraceability. Moreover, it is free from intercept-resend attack.

  6. Experimental demonstration of blind quantum computing

    NASA Astrophysics Data System (ADS)

    Barz, Stefanie; Kashefi, Elham; Broadbent, Anne; Fitzsimons, Joe; Zeilinger, Anton; Walther, Philip

    2012-02-01

    Quantum computers are among the most promising applications of quantum-enhanced technologies. Quantum effects such as superposition and entanglement enable computational speed-ups that are unattainable using classical computers. The challenges in realising quantum computers suggest that in the near future, only a few facilities worldwide will be capable of operating such devices. In order to exploit these computers, users would seemingly have to give up their privacy. It was recently shown that this is not the case and that, via the universal blind quantum computation protocol, quantum mechanics provides a way to guarantee that the user's data remain private. Here, we demonstrate the first experimental version of this protocol using polarisation-entangled photonic qubits. We demonstrate various blind one- and two-qubit gate operations as well as blind versions of the Deutsch's and Grover's algorithms. When the technology to build quantum computers becomes available, this will become an important privacy-preserving feature of quantum information processing.

  7. A Novel Quantum Proxy Blind Signature Scheme

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Xie, Shu-Cui; Zhang, Jian-Zhong

    2017-02-01

    A novel quantum proxy blind signature scheme is proposed. In this scheme, a special type of non-maximally entangled three-qubit state is introduced as a quantum channel, which can realize perfect teleportation. The message sender U blinds his message by means of preparing two groups of non-orthogonal single-photon states. According to the original signer Charlie's delegation message, the proxy signer Alice generates a corresponding signature. The arbitrator Trent can help the receiver Bob verify the signature, and also prevent Bob from doing any damage. The above-mentioned advantages make this scheme different from some existing schemes. It is showed that our scheme has the properties of undeniability, unforgeability, blindness, untraceability. Moreover, it is free from intercept-resend attack.

  8. No such thing as a "blind culture".

    PubMed

    Weisleder, Pedro

    2012-06-01

    Cochlear implant technology has altered the landscape for the Deaf and for those who provide services to the profoundly hearing impaired. As indicated by Teagle in one of the companion articles, cochlear implants afford the profoundly hearing impaired child the ability to circumvent the effects of deafness. Cochlear implants, as indicated by Lee in the other companion article, are regarded differently by members of the Deaf Community where some see the technology as a threat to Deaf Culture. Members of a different community, which comprises the visually impaired, cite lack of a common language as the main argument against the existence of a "Blind Culture." As indicated by Pierce "We [the blind] often enjoy each other's company, and we certainly spend time together working on the problems that face what we often call the 'blind community,' but I would argue that this community is different from an actual culture."

  9. Parallelization of a blind deconvolution algorithm

    NASA Astrophysics Data System (ADS)

    Matson, Charles L.; Borelli, Kathy J.

    2006-09-01

    Often it is of interest to deblur imagery in order to obtain higher-resolution images. Deblurring requires knowledge of the blurring function - information that is often not available separately from the blurred imagery. Blind deconvolution algorithms overcome this problem by jointly estimating both the high-resolution image and the blurring function from the blurred imagery. Because blind deconvolution algorithms are iterative in nature, they can take minutes to days to deblur an image depending how many frames of data are used for the deblurring and the platforms on which the algorithms are executed. Here we present our progress in parallelizing a blind deconvolution algorithm to increase its execution speed. This progress includes sub-frame parallelization and a code structure that is not specialized to a specific computer hardware architecture.

  10. Visual impairment and blindness in Hungary.

    PubMed

    Szabó, Dorottya; Sándor, Gábor László; Tóth, Gábor; Pék, Anita; Lukács, Regina; Szalai, Irén; Tóth, Georgina Zsófia; Papp, András; Nagy, Zoltán Zsolt; Limburg, Hans; Németh, János

    2017-08-21

    The aim of this study was to estimate the prevalence and causes of blindness, severe visual impairment (SVI), moderate visual impairment (MVI), and early visual impairment (EVI) and its causes in an established market economy of Europe. A cross-sectional population-based survey. A sample size of 3675 was calculated using the standard Rapid Assessment of Avoidable Blindness (RAAB) software in Hungary. A total of 105 clusters of 35 people aged 50 years or older were randomly selected with probability proportionate to size by the Hungarian Central Statistical Office. Households within the clusters were selected using compact segment sampling. Visual acuity (VA) was assessed with a Snellen tumbling E-chart with or without a pinhole in the households. The adjusted prevalences of bilateral blindness, SVI, MVI and EVI were 0.9% (95% CI: 0.6-1.2), 0.5% (95% CI: 0.2-0.7), 5.1% (95% CI: 4.3-5.9) and 6.9% (95% CI: 5.9-7.9), respectively. The major causes of blindness in Hungary were age-related macular degeneration (AMD; 27.3%) and other posterior segment diseases (27.3%), cataract (21.2%) and glaucoma (12.1%). Cataract was the main cause of SVI, MVI and EVI. Cataract surgical coverage (CSC) was 90.7%. Of all bilateral blindness in Hungary, 45.5% was considered avoidable. This study proved that RAAB methodology can be successfully conducted in industrialized countries, which often lack reliable epidemiologic data. The prevalence of blindness was relatively low, with AMD and other posterior segment diseases being the leading causes, and cataract is still a significant cause of visual impairment. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  11. Analysis of clinical data with breached blindness.

    PubMed

    Chow, Shein-Chung; Shao, Jun

    2004-04-30

    In clinical trials, blinding is usually employed to prevent bias that may be introduced due to the knowledge of the identity of the treatment codes. This bias could alter the conclusion of statistical inference on the treatment effect. The purpose of this article is to propose a method for analysing clinical data with breached blindness. The example regarding the study of the effectiveness of an appetite suppressant in weight loss in obese woman as described in Brownell and Stunkard (Am. J. Psychiatry 1982; 139:1487-1489) is used to illustrate the application of the proposed methods.

  12. Transform domain steganography with blind source separation

    NASA Astrophysics Data System (ADS)

    Jouny, Ismail

    2015-05-01

    This paper applies blind source separation or independent component analysis for images that may contain mixtures of text, audio, or other images for steganography purposes. The paper focuses on separating mixtures in the transform domain such as Fourier domain or the Wavelet domain. The study addresses the effectiveness of steganography when using linear mixtures of multimedia components and the ability of standard blind sources separation techniques to discern hidden multimedia messages. Mixing in the space, frequency, and wavelet (scale) domains is compared. Effectiveness is measured using mean square error rate between original and recovered images.

  13. The sensory construction of dreams and nightmare frequency in congenitally blind and late blind individuals.

    PubMed

    Meaidi, Amani; Jennum, Poul; Ptito, Maurice; Kupers, Ron

    2014-05-01

    We aimed to assess dream content in groups of congenitally blind (CB), late blind (LB), and age- and sex-matched sighted control (SC) participants. We conducted an observational study of 11 CB, 14 LB, and 25 SC participants and collected dream reports over a 4-week period. Every morning participants filled in a questionnaire related to the sensory construction of the dream, its emotional and thematic content, and the possible occurrence of nightmares. We also assessed participants' ability of visual imagery during waking cognition, sleep quality, and depression and anxiety levels. All blind participants had fewer visual dream impressions compared to SC participants. In LB participants, duration of blindness was negatively correlated with duration, clarity, and color content of visual dream impressions. CB participants reported more auditory, tactile, gustatory, and olfactory dream components compared to SC participants. In contrast, LB participants only reported more tactile dream impressions. Blind and SC participants did not differ with respect to emotional and thematic dream content. However, CB participants reported more aggressive interactions and more nightmares compared to the other two groups. Our data show that blindness considerably alters the sensory composition of dreams and that onset and duration of blindness plays an important role. The increased occurrence of nightmares in CB participants may be related to a higher number of threatening experiences in daily life in this group. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. The Sokoto blind beggars: causes of blindness and barriers to rehabilitation services.

    PubMed

    Balarabe, Aliyu Hamza; Mahmoud, Abdulraheem O; Ayanniyi, Abdulkabir Ayansiji

    2014-01-01

    To determine the causes of blindness and the barriers to accessing rehabilitation services (RS) among blind street beggars (bsb) in Sokoto, Nigeria. A cross-sectional survey of 202 bsb (VA < 3/60) using interviewer administered questionnaire. The causes of blindness were diagnosed by clinical ophthalmic examination. There were 107 (53%) males and 95 (47%) females with a mean age of 49 years (SD 12.2). Most bsb 191 (94.6%) had non-formal education. Of 190 (94.1%) irreversibly bsb, 180/190 (94.7%) had no light perception (NPL) bilaterally. The major causes of blindness were non-trachomatous corneal opacity (60.8%) and trachoma corneal opacity (12.8%). There were 166 (82%) blind from avoidable causes and 190 (94.1%) were irreversibly blind with 76.1% due to avoidable causes. The available sub-standard RS were educational, vocational and financial support. The barriers to RS in the past included non-availability 151 (87.8%), inability to afford 2 (1.2%), unfelt need 4 (2.3%), family refusal 1 (0.6), ignorance 6 (3.5%) and being not linked 8 (4.7%). The barriers to RS during the study period included inability of 72 subjects (35.6%) to access RS and 59 (81.9%) were due to lack of linkage to the existing services. Corneal opacification was the major cause of blindness among bsb. The main challenges to RS include the inadequate services available, societal and users factors. Renewed efforts are warranted toward the prevention of avoidable causes of blindness especially corneal opacities. The quality of life of the blind street beggar should be improved through available, accessible and affordable well-maintained and sustained rehabilitation services.

  15. The Sokoto Blind Beggars: Causes of Blindness and Barriers to Rehabilitation Services

    PubMed Central

    Balarabe, Aliyu Hamza; Mahmoud, Abdulraheem O.; Ayanniyi, Abdulkabir Ayansiji

    2014-01-01

    Purpose: To determine the causes of blindness and the barriers to accessing rehabilitation services (RS) among blind street beggars (bsb) in Sokoto, Nigeria. Materials and Methods: A cross-sectional survey of 202 bsb (VA < 3/60) using interviewer administered questionnaire. The causes of blindness were diagnosed by clinical ophthalmic examination. Results: There were 107 (53%) males and 95 (47%) females with a mean age of 49 years (SD 12.2). Most bsb 191 (94.6%) had non-formal education. Of 190 (94.1%) irreversibly bsb, 180/190 (94.7%) had no light perception (NPL) bilaterally. The major causes of blindness were non-trachomatous corneal opacity (60.8%) and trachoma corneal opacity (12.8%). There were 166 (82%) blind from avoidable causes and 190 (94.1%) were irreversibly blind with 76.1% due to avoidable causes. The available sub-standard RS were educational, vocational and financial support. The barriers to RS in the past included non-availability 151 (87.8%), inability to afford 2 (1.2%), unfelt need 4 (2.3%), family refusal 1 (0.6), ignorance 6 (3.5%) and being not linked 8 (4.7%). The barriers to RS during the study period included inability of 72 subjects (35.6%) to access RS and 59 (81.9%) were due to lack of linkage to the existing services. Conclusion: Corneal opacification was the major cause of blindness among bsb. The main challenges to RS include the inadequate services available, societal and users factors. Renewed efforts are warranted toward the prevention of avoidable causes of blindness especially corneal opacities. The quality of life of the blind street beggar should be improved through available, accessible and affordable well-maintained and sustained rehabilitation services. PMID:24791106

  16. ID-Based Blind Signature and Proxy Blind Signature without Trusted PKG

    NASA Astrophysics Data System (ADS)

    Yu, Yihua; Zheng, Shihui; Yang, Yixian

    Private key escrow is an inherent disadvantage for ID-based cryptosystem, i.e., the PKG knows each signer's private key and can forge the signature of any signer. Blind signature plays a central role in electronic cash system. Private key escrow is more severe in electronic cash system since money is directly involved. To avoid the key escrow problem, we propose an ID-based blind signature and proxy blind signature without trusted PKG. If the dishonest PKG impersonates an honest signer to sign a document, the signer can provide a proof to convince that the PKG is dishonest.

  17. Does semantic preactivation reduce inattentional blindness?

    PubMed

    Kreitz, Carina; Schnuerch, Robert; Furley, Philip A; Gibbons, Henning; Memmert, Daniel

    2015-04-01

    We are susceptible to failures of awareness if a stimulus occurs unexpectedly and our attention is focused elsewhere. Such inattentional blindness is modulated by various parameters, including stimulus attributes, the observer's cognitive resources, and the observer's attentional set regarding the primary task. In three behavioral experiments with a total of 360 participants, we investigated whether mere semantic preactivation of the color of an unexpected object can reduce inattentional blindness. Neither explicitly mentioning the color several times before the occurrence of the unexpected stimulus nor priming the color more implicitly via color-related concepts could significantly reduce the susceptibility to inattentional blindness. Even putting the specific color concept in the main focus of the primary task did not lead to reduced inattentional blindness. Thus, we have shown that the failure to consciously perceive unexpected objects was not moderated by semantic preactivation of the objects' most prominent feature: its color. We suggest that this finding reflects the rather general principle that preactivations that are not motivationally relevant for one's current selection goals do not suffice to make an unexpected object overcome the threshold of awareness.

  18. Cognitive Development in Deaf-Blind Children.

    ERIC Educational Resources Information Center

    Rittenhouse, Robert K.

    The paper reviews the literature and proposes a study on how nonlanguage deaf/blind children (ages 2 to 14) match and classify, the age at which the skills are reached, and the role of language in the process. The theories of J. Piaget and J. Bruner on the importance of language in stage development are explored. The Ss would be matched for age…

  19. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Dr. Marc Mauer, president of the National Federation of the Blind, left, accepts two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009 from NASA Associate Administrator Chris Scolese, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  20. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    NASA astronaut Greg Johnson, at podium, speaks at a ceremony where senior NASA officials presented the National Federation of the Blind with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  1. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Chris Scolese, NASA Associate Administrator, speaks at a ceremony where senior NASA officials presented the National Federation of the Blind with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  2. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Chris Scolese, NASA Associate Administrator, speaks at a ceremony where senior NASA officials presented the National Federation of the Blind, with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  3. The global state of cataract blindness.

    PubMed

    Lee, Cameron M; Afshari, Natalie A

    2017-01-01

    Cataracts are a significant cause of blindness and visual impairment worldwide. The present article reviews the literature and describes the current extent of cataracts globally, barriers to treatment, and recommendations for improving the treatment of cataracts. Prevalence and absolute number of blind because of cataracts remain high, although rates are declining in many areas globally. The age-standardized prevalence of blindness in adults older than 50 remains highest in western sub-Saharan Africa, with a rate of 6.0%. The greatest declines in age-standardized blindness because of cataracts in adults older than 50 between 1990 and 2010 were in East Asia, tropical Latin America, and western Europe. Recent studies have largely found higher rates of cataracts in women than in men. A new simulator for training ophthalmologists in manual small-incision cataract surgery holds promise for the future. The rates of cataract surgery are increasing and postoperative outcomes are improving worldwide, yet challenges to reducing the cataract burden further remain. Cost, an insufficient number of ophthalmologists, and low government funding remain significant barriers but investment in further eye care infrastructure and training of additional ophthalmologists would improve the current situation.

  4. Mobility and Orientation Instruction of Blind Persons.

    ERIC Educational Resources Information Center

    Luini, Eugene; Ryder, James

    A peripatologist taught 102 blind and partially sighted individuals of all ages mobility and orientation techniques. Volunteers assisted with transportation, followup, consultation, and direct teaching of mobility. Over a 3-year period, the number of lessons per client varied from one to 86, and the number of hours spent by the instructor in…

  5. Deaf-Blind Perspectives, 2001-2002.

    ERIC Educational Resources Information Center

    Malloy, Peggy, Ed.

    2002-01-01

    Three issues of this newsletter on deaf-blind issues include announcements, reviews, news items, and the following articles: "'What's My Role?' A Comparison of the Responsibilities of Interpreters, Interveners, and Support Service Providers" (Susanne Morgan); "A Support Service Provider Program in Utah" (Cordie Weed);…

  6. Pattern Perception and Pictures for the Blind

    ERIC Educational Resources Information Center

    Heller, Morton A.; McCarthy, Melissa; Clark, Ashley

    2005-01-01

    This article reviews recent research on perception of tangible pictures in sighted and blind people. Haptic picture naming accuracy is dependent upon familiarity and access to semantic memory, just as in visual recognition. Performance is high when haptic picture recognition tasks do not depend upon semantic memory. Viewpoint matters for the ease…

  7. My Blindness? No More than an Inconvenience

    ERIC Educational Resources Information Center

    Weller, Jamie

    2005-01-01

    A blind ex-service man gives an account of the onset of cone dystrophy which brought an end to his career as an aircraft engineer. He tells of his rehabilitation and training in residential settings, of the acquisition of new skills, and of studying to gain a bachelor's degree, and of setting out on an entirely new professional career. What…

  8. Deaf Blind Children: Evaluating Their Multiple Handicaps.

    ERIC Educational Resources Information Center

    Curtis, Scott, Ed.; And Others

    Prepared by specialists on the evaluation team at the Syracuse University Center for the Development of Blind Children, the book describes the procedures of the special diagnostic clinic within this unit. The diagnostic clinic was established to provide a unified approach to the evaluation and study of multiply handicapped children. Described in…

  9. Postural Determinants in the Blind. Final Report.

    ERIC Educational Resources Information Center

    Siegel, Irwin M.; Murphy, Thomas J.

    The problem of malposture in the blind and its affect on orientation and travel skills was explored. A group of 45 students were enrolled in a standard 3-month mobility training program. Each student suffered a postural problem, some compounded by severe orthopedic and/or neurological deficit. All subjects were given complete orthopedic and…

  10. Graphic Biology Laboratory Modules for the Blind.

    ERIC Educational Resources Information Center

    Brooks, Austin E.

    The goal of this project was to devise new methods of producing tactile facsimiles of microscopic images for the blind and visually impaired biology students at the secondary and college level. The numerous raised-line images that were produced were assembled along with brailled and large print student instructions, audio cassette tapes describing…

  11. Default brain functionality in blind people.

    PubMed

    Burton, H; Snyder, A Z; Raichle, M E

    2004-10-26

    We studied whether default functionality of the human brain, as revealed by task-independent decreases in activity occurring during goal-directed behaviors, is functionally reorganized by blindness. Three groups of otherwise normal adults were studied: early blind, adventitiously blind, and normally sighted. They were imaged by using functional MRI during performance of a word association task (verb generation to nouns) administered by using auditory stimuli in all groups and Braille reading in blind participants. In sighted people, this task normally produces robust task-independent decreases relative to a baseline of quiet wakefulness with eyes closed. Our functional MRI results indicate that task-independent decreases are qualitatively similar across all participant groups in medial and dorsal prefrontal, lateral parietal, anterior precuneus, and posterior cingulate cortices. Similarities in task-independent decreases are consistent with the hypothesis that functional reorganization resulting from the absence of a particular sensory modality does not qualitatively affect default functionality as revealed by task-independent decreases. More generally, these results support the notion that the brain largely operates intrinsically, with sensory information modulating rather than determining system operations.

  12. Audiological Assessment of Deaf-Blind Children.

    ERIC Educational Resources Information Center

    Bernstein, Phyllis F.; Roeser, Ross J.

    The audiological assessment of 50 deaf blind children, 6 months to 14 years of age, in an outpatient setting is described, as are testing procedures and results. Etiological factors are given which include maternal rubella (accounting for 27 children), meningitis, prematurity, neonatal anoxia, and Rh incompatability. Discussed are the following…

  13. Mental Imagery in Congenitally Blind Children.

    ERIC Educational Resources Information Center

    Anderson, David W.

    1984-01-01

    The study of blind children's (ages 3-9) memory of objects was invested with personalized meaning related to previous encounters with the objects. The language they used reflected that experience and their form of mental representation rather than their knowledge of the language used by sighted people. (CL)

  14. Drilling at right angles in blind holes

    NASA Technical Reports Server (NTRS)

    Pessin, R.

    1981-01-01

    Tool drills small hole perpendicular to and at bottom of blind hole. It consists of carbide cutter brazed to flexible shaft, inside thin metal tube with 90 degree bend. Wood dowel holds tube while motor turns shaft and drives cutter. It was developed for clearing plugged fuel orifices. Concept is adaptable to other hard-to-reach drilling situations.

  15. Blind Quantum Computing with Weak Coherent Pulses

    NASA Astrophysics Data System (ADS)

    Dunjko, Vedran; Kashefi, Elham; Leverrier, Anthony

    2012-05-01

    The universal blind quantum computation (UBQC) protocol [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual IEEE Symposiumon Foundations of Computer Science (IEEE Computer Society, Los Alamitos, CA, USA, 2009), pp. 517-526.] allows a client to perform quantum computation on a remote server. In an ideal setting, perfect privacy is guaranteed if the client is capable of producing specific, randomly chosen single qubit states. While from a theoretical point of view, this may constitute the lowest possible quantum requirement, from a pragmatic point of view, generation of such states to be sent along long distances can never be achieved perfectly. We introduce the concept of ɛ blindness for UBQC, in analogy to the concept of ɛ security developed for other cryptographic protocols, allowing us to characterize the robustness and security properties of the protocol under possible imperfections. We also present a remote blind single qubit preparation protocol with weak coherent pulses for the client to prepare, in a delegated fashion, quantum states arbitrarily close to perfect random single qubit states. This allows us to efficiently achieve ɛ-blind UBQC for any ɛ>0, even if the channel between the client and the server is arbitrarily lossy.

  16. Deaf-Blind Perspectives. 1996-97.

    ERIC Educational Resources Information Center

    Deaf-Blind Perspectives, 1996

    1996-01-01

    Three issues of this newsletter include articles on and news items related to deaf-blindness. Articles include the following: "Research-to-Practice: Bridging the Gap between Research and Demonstration Projects and Practical Needs of Parents and Educators" (Harvey Mar and Nancy Sall); "Syndromes, Behavior, and Educational Intervention" (J. P. M.…

  17. Cognitive Development in Deaf-Blind Children.

    ERIC Educational Resources Information Center

    Rittenhouse, Robert K.

    The paper reviews the literature and proposes a study on how nonlanguage deaf/blind children (ages 2 to 14) match and classify, the age at which the skills are reached, and the role of language in the process. The theories of J. Piaget and J. Bruner on the importance of language in stage development are explored. The Ss would be matched for age…

  18. Environmental Programming for the Deaf-Blind.

    ERIC Educational Resources Information Center

    Michigan School for the Blind, Lansing.

    Presented are the proceedings of an environmental programing workshop on deaf blind individuals at which principles, techniques, and examples of behavior modification were discussed and demonstrated. Rules for data collection are given as well as explanations of the categorizing, the measuring devices, and the data sheets involved in behavior…

  19. Blind quantum computing with weak coherent pulses.

    PubMed

    Dunjko, Vedran; Kashefi, Elham; Leverrier, Anthony

    2012-05-18

    The universal blind quantum computation (UBQC) protocol [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual IEEE Symposiumon Foundations of Computer Science (IEEE Computer Society, Los Alamitos, CA, USA, 2009), pp. 517-526.] allows a client to perform quantum computation on a remote server. In an ideal setting, perfect privacy is guaranteed if the client is capable of producing specific, randomly chosen single qubit states. While from a theoretical point of view, this may constitute the lowest possible quantum requirement, from a pragmatic point of view, generation of such states to be sent along long distances can never be achieved perfectly. We introduce the concept of ϵ blindness for UBQC, in analogy to the concept of ϵ security developed for other cryptographic protocols, allowing us to characterize the robustness and security properties of the protocol under possible imperfections. We also present a remote blind single qubit preparation protocol with weak coherent pulses for the client to prepare, in a delegated fashion, quantum states arbitrarily close to perfect random single qubit states. This allows us to efficiently achieve ϵ-blind UBQC for any ϵ>0, even if the channel between the client and the server is arbitrarily lossy.

  20. The Body-Image of Blind Children.

    ERIC Educational Resources Information Center

    Cratty, Bryant J.; Sams, Theressa A.

    To develop an assessment device for the evaluation of body image, to evaluate the body image of blind children, to make comparisons between subgroups (sex, age, IQ) and to derive sequences of tasks related to body image training, 91 children (mean age 10.06 years, mean IQ 88.32) were evaluated by a body image survey form. Analysis of the data…

  1. What Art Three Blind Mice Up To?

    ERIC Educational Resources Information Center

    Peace, Suze

    1998-01-01

    Offers an integrated art lesson in which kindergarten students drew a picture in response to the "Three Blind Mice" using geometric shapes for the mice. Summarizes the technique used to create the mice and focuses on mixing colors to introduce tints and shading to the students. (CMK)

  2. Why Art Education for the Elderly Blind?

    ERIC Educational Resources Information Center

    Aspell, Amy S.

    1976-01-01

    Identification and analysis of types of problems blind populations encounter, through literature on the topic and observation, leads one to the unexpected conclusion that art can play an essential role in the amelioration of these problems. Art and craft activities can provide a process of self-analysis for therapy toward adjustment. (Author)

  3. Expert Blind Spot among Preservice Teachers

    ERIC Educational Resources Information Center

    Nathan, Mitchell J.; Petrosino, Anthony

    2003-01-01

    This study (N = 48) examined the relationship between preservice secondary teachers' subject-matter expertise in mathematics and their judgments of students' algebra problem-solving difficulty. As predicted by the "expert blind spot" hypothesis, participants with more advanced mathematics education, regardless of their program affiliation or…

  4. Training Blind Adolescents in Social Skills.

    ERIC Educational Resources Information Center

    Van Hasselt, Vincent B.; And Others

    1983-01-01

    Social skills training four blind unassertive adolescent females include instructions, feedback, behavior rehearsal, modeling, and manual guidance. Most behaviors selected for modification changed markedly, although some decreased after four weeks, requiring "booster" sessions to promote a return to posttreatment levels. (Author/CL)

  5. [Recreation for Youth with Deaf Blindness.

    ERIC Educational Resources Information Center

    Carr, Theresa, Ed.

    1992-01-01

    This newsletter special issue focuses on recreational programming for people with deaf blindness. The following individual articles are presented: "Strategies To Promote Community Integrated Recreation: Guidelines for Leisure Coaches" by Joann Enos (which lists seven such strategies); "Assessing Recreation and Leisure…

  6. Terminology and the Psychosocial Burden of Blindness

    ERIC Educational Resources Information Center

    Bolt, David

    2004-01-01

    Various denotations and connotations of the word "blindness" are examined and the inference is drawn that they constitute a psychosocial burden that perpetuates prejudice. The analysis leads on to a hypothesis in which a more progressive terminology could lead to reduction of this burden.

  7. Training Blind and Visually Handicapped Computer Programmers.

    ERIC Educational Resources Information Center

    Charlston, Stewart E.; And Others

    The state of California and System Development Corporation have developed, implemented, and evaluated a training program in computer programing for the blind and visually impaired. Students are selected according to general aptitude, interests, general intelligence, previous educational achievement, health, and personal qualities. The eight-month…

  8. My Blindness? No More than an Inconvenience

    ERIC Educational Resources Information Center

    Weller, Jamie

    2005-01-01

    A blind ex-service man gives an account of the onset of cone dystrophy which brought an end to his career as an aircraft engineer. He tells of his rehabilitation and training in residential settings, of the acquisition of new skills, and of studying to gain a bachelor's degree, and of setting out on an entirely new professional career. What…

  9. Potentials of Rubella Deaf-Blind Children.

    ERIC Educational Resources Information Center

    Smith, Benjamin F.

    Potentials of three classifications of rubella deaf blind children are discussed. Potentials for children at the middle trainable level and below are discussed for the areas of communication skills, daily living skills, mobility and orientation, vocational effort, and self-control and social interaction. For children in the upper trainable through…

  10. Leading Causes of Blindness | NIH MedlinePlus the Magazine

    MedlinePlus

    ... turn Javascript on. Feature: Vision Leading Causes of Blindness Past Issues / Winter 2012 Table of Contents Cataract ... have cataracts. They are the leading cause of blindness in the world. By age 80, more than ...

  11. Research on solar-blind UV optical imaging system

    NASA Astrophysics Data System (ADS)

    Wang, Baohua; Wang, Yuanyuan; Zhong, Xiaoming; Ruan, Ningjuan

    2015-02-01

    Solar blind UV detecting system has many advantages such as strong environmental adaptability, low error rate, small volume and without refrigeration. To in-depth develop UV solar blind detection system research work has important significance for further improving solar blind UV detection technology. The working principle of solar blind UV detection system and the basic components were introduced firstly, and then the key technology of solar blind UV detection system was deeply analyzed. Finally, large coverage solar blind UV optical imaging system was designed according to the actual demand for greater coverage of the solar blind UV detection system. The result shows that the system has good imaging quality, simple and compact structure. This system can be used in various types of solar blind UV detection system, and is of high application value.

  12. Men and antiretroviral therapy in Africa: our blind spot.

    PubMed

    Cornell, Morna; McIntyre, James; Myer, Landon

    2011-07-01

    Most antiretroviral therapy (ART)-related policies remain blind to men's treatment needs. Global and national programmes need to address this blindness urgently, to ensure equitable access to ART in Africa.

  13. Blind College Students--Counseling and Guidance Approaches

    ERIC Educational Resources Information Center

    Dailey, Louise

    1977-01-01

    This article discusses the personal, academic, mechanical, and placement support needed by blind college students. Financial, community, and commercial resources are identified, and suggestions are offered to counselors for developing programs that enhance faculty sensitivity and blind student development. (Author)

  14. Concepts about Print for the Young Blind Child.

    ERIC Educational Resources Information Center

    Language Arts, 1982

    1982-01-01

    Provides teachers with an understanding of how sighted children develop concepts about print and how blind children develop concepts about braille. Prereading activities designed to extend young children's concepts about print are adapted for blind children. (HTH)

  15. Non-optical releasers for aggressive behavior in blind and blinded Astyanax (Teleostei, Characidae).

    PubMed

    Espinasa, Luis; Yamamoto, Yoshiyuki; Jeffery, William R

    2005-09-30

    Prior to this study, it was believed that epigean and hypogean Astyanax differ markedly in their display of agonistic behavior. Research suggested that surface-dwelling individuals were extremely aggressive whereas their blind, cave-dwelling counterparts tended to show little or no aggressive behavior. Aggression in Astyanax was thought to be triggered by visual stimuli because surface fish in a dark environment or surface fish blinded late in life did not show aggression. Here, we demonstrate that surface fish blinded early on in their embryonic development are highly aggressive as adults. We also report the first case of a population of blind cave-dwelling Astyanax that is highly aggressive. We conclude that reduced aggression is not the only evolutionary pathway for troglobitic Astyanax and that there is some degree of developmental plasticity in the releaser of aggression and in the selection of its triggering stimuli.

  16. The Economic Impact of Blindness in Europe.

    PubMed

    Chakravarthy, Usha; Biundo, Eliana; Saka, Rasit Omer; Fasser, Christina; Bourne, Rupert; Little, Julie-Anne

    2017-08-01

    To estimate the annual loss of productivity from blindness and moderate to severe visual impairment (MSVI) in the population aged >50 years in the European Union (EU). We estimated the cost of lost productivity using three simple models reported in the literature based on (1) minimum wage (MW), (2) gross national income (GNI), and (3) purchasing power parity-adjusted gross domestic product (GDP-PPP) losses. In the first two models, assumptions included that all individuals worked until 65 years of age, and that half of all visual impairment cases in the >50-year age group would be in those aged between 50 and 65 years. Loss of productivity was estimated to be 100% for blind individuals and 30% for those with MSVI. None of these models included direct medical costs related to visual impairment. The estimated number of blind people in the EU population aged >50 years is ~1.28 million, with a further 9.99 million living with MSVI. Based on the three models, the estimated cost of blindness is €7.81 billion, €6.29 billion and €17.29 billion and that of MSVI €18.02 billion, €24.80 billion and €39.23 billion, with their combined costs €25.83 billion, €31.09 billion and €56.52 billion, respectively. The estimates from the MW and adjusted GDP-PPP models were generally comparable, whereas the GNI model estimates were higher, probably reflecting the lack of adjustment for unemployment. The cost of blindness and MSVI in the EU is substantial. Wider use of available cost-effective treatment and prevention strategies may reduce the burden significantly.

  17. [Embedded system design of color-blind image processing].

    PubMed

    Wang, Eric; Ma, Yu; Wang, Yuanyuan

    2011-01-01

    An ARM-based embedded system design schemes is proposed for the color-blind image processing system. The hardware and software of the embedded color-blind image processing system are designed using ARM core processor. Besides, a simple and convenient interface is implemented. This system supplies a general hardware platform for the applications of color-blind image processing algorithms, so that it may bring convenience for the test and rectification of color blindness.

  18. Poverty and Blindness in Nigeria: Results from the National Survey of Blindness and Visual Impairment.

    PubMed

    Tafida, A; Kyari, F; Abdull, M M; Sivasubramaniam, S; Murthy, G V S; Kana, I; Gilbert, Clare E

    2015-01-01

    Poverty can be a cause and consequence of blindness. Some causes only affect the poorest communities (e.g. trachoma), and poor individuals are less likely to access services. In low income countries, cataract blind adults have been shown to be less economically active, indicating that blindness can exacerbate poverty. This study aims to explore associations between poverty and blindness using national survey data from Nigeria. Participants ≥40 years were examined in 305 clusters (2005-2007). Sociodemographic information, including literacy and occupation, was obtained by interview. Presenting visual acuity (PVA) was assessed using a reduced tumbling E LogMAR chart. Full ocular examination was undertaken by experienced ophthalmologists on all with PVA <6/12 in either eye. Causes of vision loss were determined using World Health Organization guidelines. Households were categorized into three levels of poverty based on literacy and occupation at household level. A total of 569/13,591 participants were blind (PVA <3/60, better eye; prevalence 4.2%, 95% confidence interval [CI] 3.8-4.6%). Prevalences of blindness were 8.5% (95% CI 7.7-9.5%), 2.5% (95% CI 2.0-3.1%), and 1.5% (95% CI 1.2-2.0%) in poorest, medium and affluent households, respectively (p = 0.001). Cause-specific prevalences of blindness from cataract, glaucoma, uncorrected aphakia and corneal opacities were significantly higher in poorer households. Cataract surgical coverage was low (37.2%), being lowest in females in poor households (25.3%). Spectacle coverage was 3 times lower in poor than affluent households (2.4% vs. 7.5%). In Nigeria, blindness is associated with poverty, in part reflecting lower access to services. Reducing avoidable causes will not be achieved unless access to services improves, particularly for the poor and women.

  19. The feasibility of external blind DNA proficiency testing. II. Experience with actual blind tests.

    PubMed

    Peterson, Joseph L; Lin, George; Ho, Monica; Chen, Yingyu; Gaensslen, R E

    2003-01-01

    The background and goals of a national study to determine the feasibility of blind proficiency testing in U.S. forensic DNA laboratories are discussed. Part of the project involved designing and executing a series of fifteen blind proficiency tests. Execution included biological specimen donor recruitment and case evidence manufacturing. Simulated cases were submitted to DNA laboratories by law enforcement agencies and in some cases by other forensic-science laboratories. Replicate-manufactured evidence was submitted to reference laboratories to simulate the workings of a larger-scale program. Ten tests were straightforward, and essentially tested analytical ability. Five tests involved selecting on the basis of case facts appropriate bloodstains for typing from a bloodstain pattern. We describe in detail our experience in designing and conducting these blind proficiency test trials, and relate those experiences to the overall issue of blind proficiency testing as a quality-assurance tool in forensic DNA laboratories. In this feasibility test series, one blind test was detected by a laboratory, a second one was shown to the lab by law enforcement, and a third was never completed because of lapses in communication. Turnaround times were relatively fast in the independent/commercial labs and relatively slow in the larger public laboratories. Two cross-state case-to-case CODIS "hits" were "planted" among the first series of ten blind tests. One pair was detected. One member of the second pair went to a lab that was not CODIS-ready.

  20. THE SELECTION, TRAINING, AND PLACEMENT OF BLIND COMPUTER PROGRAMMERS.

    ERIC Educational Resources Information Center

    Kansas State Univ., Manhattan.

    FINDINGS OF A 2-YEAR STUDY ON THE SELECTION, TRAINING, AND EMPLOYMENT OF BLIND PERSONS IN THE COMPUTER RELATED PROFESSIONS ARE REPORTED FOR USE AS A GUIDE FOR THE TEACHER OF COMPUTER PROFESSIONALS, THE EMPLOYER WHO SEEKS TO MAKE USE OF EMPLOYEES' SKILLS, THE REHABILITATION WORKER WHO WILL GUIDE THE BLIND PERSON, AND THE BLIND PERSON WHO CHOOSES…

  1. Characteristics of Individuals with Congenital and Acquired Deaf-Blindness

    ERIC Educational Resources Information Center

    Dalby, Dawn M.; Hirdes, John P.; Stolee, Paul; Strong, J. Graham; Poss, Jeff; Tjam, Erin Y.; Bowman, Lindsay; Ashworth, Melody

    2009-01-01

    Using a standardized assessment instrument, the authors compared 182 adults with congenital deaf-blindness and those with acquired deaf-blindness. They found that those with congenital deaf-blindness were more likely to have impairments in cognition, activities of daily living, and social interactions and were less likely to use speech for…

  2. 42 CFR 435.531 - Determinations of blindness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Determinations of blindness. 435.531 Section 435... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.531 Determinations of blindness. (a) Except as specified in paragraph (b) of this section, in determining blindness— (1) A...

  3. 42 CFR 435.531 - Determinations of blindness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Determinations of blindness. 435.531 Section 435... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.531 Determinations of blindness. (a) Except as specified in paragraph (b) of this section, in determining blindness— (1) A...

  4. 42 CFR 435.531 - Determinations of blindness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Determinations of blindness. 435.531 Section 435... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.531 Determinations of blindness. (a) Except as specified in paragraph (b) of this section, in determining blindness— (1) A...

  5. 42 CFR 435.531 - Determinations of blindness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Determinations of blindness. 435.531 Section 435... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.531 Determinations of blindness. (a) Except as specified in paragraph (b) of this section, in determining blindness— (1) A...

  6. 42 CFR 435.531 - Determinations of blindness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Determinations of blindness. 435.531 Section 435... ISLANDS, AND AMERICAN SAMOA Categorical Requirements for Eligibility Blindness § 435.531 Determinations of blindness. (a) Except as specified in paragraph (b) of this section, in determining blindness— (1) A...

  7. Raising the Welfare of the Blind in the USSR.

    ERIC Educational Resources Information Center

    Zimin, B.

    Described are activities and plans of the All-Russia Society for the Blind. Noted is the changing composition of society membership in the direction of more members past 60 years of age and fewer children blinded at birth or early childhood. It is reported that all the blind who wish work are employed, and that the society provides professional…

  8. Recreation for Blind Adults. Organized Programs in Specialized Settings.

    ERIC Educational Resources Information Center

    Case, Maurice

    The effects of blindness in adults, activity programs, and the administrative technicalities of these programs are discussed. A definition of blindness, historical background, and mention of social group work serve as introduction to the impact of blindness. Under these activities are included the following subjects: arts and crafts, study and…

  9. 34 CFR 395.11 - Training program for blind individuals.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... education and additional training or retraining for improved work opportunities) for all blind licensees... 34 Education 2 2010-07-01 2010-07-01 false Training program for blind individuals. 395.11 Section... BLIND ON FEDERAL AND OTHER PROPERTY The State Licensing Agency § 395.11 Training program for...

  10. Characteristics of Individuals with Congenital and Acquired Deaf-Blindness

    ERIC Educational Resources Information Center

    Dalby, Dawn M.; Hirdes, John P.; Stolee, Paul; Strong, J. Graham; Poss, Jeff; Tjam, Erin Y.; Bowman, Lindsay; Ashworth, Melody

    2009-01-01

    Using a standardized assessment instrument, the authors compared 182 adults with congenital deaf-blindness and those with acquired deaf-blindness. They found that those with congenital deaf-blindness were more likely to have impairments in cognition, activities of daily living, and social interactions and were less likely to use speech for…

  11. Ya "See" What We Mean: Teaching the Blind to Ski.

    ERIC Educational Resources Information Center

    Pringle, Doug; Winthers, Jim

    The illustrated manual contains instructions for teaching blind and partially sighted students to ski. It is noted that blind students should be coached, instructed, and encouraged in the same manner as sighted students although additional safety precautions should be employed. Psychological implications for the blind student learning to ski are…

  12. Programs for Deaf-Blind Children and Adults.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1999

    1999-01-01

    This directory of programs for deaf-blind children and adults lists program name, address, telephone numbers, e-mail address, Web site, and administrator name. The directory also lists, with similar information, Helen Keller Centers for Deaf-Blind Youth and Adults, and programs for training teachers of deaf-blind students. (DB)

  13. Causes of blindness in a special education school.

    PubMed

    Onakpoya, O H; Adegbehingbe, B O; Omotoye, O J; Adeoye, A O

    2011-01-01

    Blind children and young adults have to overcome a lifetime of emotional, social and economic difficulties. They employ non-vision dependent methods for education. To assess the causes of blindness in a special school in southwestern Nigeria to aid the development of efficient blindness prevention programmes. A cross-sectional survey of the Ekiti State Special Education School, Nigeria was conducted in May-June 2008 after approval from the Ministry of Education. All students in the blind section were examined for visual acuity, pen-torch eye examination and dilated fundoscopy in addition to taking biodata and history. Thirty blind students with mean age of 18±7.3 years and male: female ratio of 1.7:1 were examined. Blindness resulted commonly from cataract eight (26.7%), glaucoma six (20%) retinitis pigmentosa four (16.7%) and posttraumatic phthysis bulbi two (6.7%). Blindness was avoidable in 18 (61%) of cases. Glaucoma blindness was associated with redness, pain, lacrimation and photophobia in 15 (50%) and hyphaema in 16.7% of students; none of these students were on any medication at the time of study. The causes of blindness in rehabilitation school for the blind are largely avoidable and glaucoma-blind pupils face additional painful eye related morbidity during rehabilitation. While preventive measures and early intervention are needful against childhood cataract and glaucoma, regular ophthalmic consultations and medications are needed especially for glaucoma blind pupils.

  14. Programs for Deaf-Blind Children and Adults.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1998

    1998-01-01

    This directory of programs for deaf-blind children and adults lists these programs alphabetically by state. It also lists Helen Keller Centers for Deaf Blind Youth and Adults and programs for training teachers of deaf-blind students. Complete contact information (names, addresses, telephone numbers, e-mail, Web site) is provided. (DB)

  15. Programs for Deaf-Blind Children and Adults.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1993

    1993-01-01

    The 1992-93 directory of programs for children and adults with deaf-blindness lists (1) 27 state or multistate programs; (2) the national headquarters and the 10 regional offices of the Helen Keller National Center for Deaf Blind Youth and Adults; and (3) seven programs for training teachers of deaf blind students. (DB)

  16. Programs for Deaf-blind Children and Adults.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 2001

    2001-01-01

    This directory provides information on programs for deaf-blind children and adults including national and state programs, the Helen Keller Centers for Deaf-Blind Youth and Adults, and programs for training teachers of deaf-blind students. Within each broad category, programs are listed alphabetically by state and provide detailed contact…

  17. Programs for Deaf-Blind Children and Adults.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 1994

    1994-01-01

    This directory lists programs for deaf-blind children and youth, regional offices of the Helen Keller National Center for Deaf-Blind Youth and Adults, and programs for training teachers of deaf-blind students. Programs are listed alphabetically by state, with contact information provided. (DB)

  18. OUR BLIND CHILDREN, GROWING AND LEARNING WITH THEM.

    ERIC Educational Resources Information Center

    LOWENFELD, BERTHOLD

    WRITTEN AS AN AID TO PARENTS, THIS BOOK PRESENTS FACTS ON BLINDNESS AND PRACTICAL INFORMATION ON THE REARING OF BLIND CHILDREN FROM INFANCY THROUGH ADOLESCENCE. INFORMATION IS GIVEN ABOUT TEACHING BLIND CHILDREN SKILLS AND HABITS RELATED TO EATING, TOILET TRAINING, SLEEPING, DRESSING, WALKING, TALKING, AND PLAYING. SCHOOLING AND RELATED QUESTIONS…

  19. 20 CFR 416.981 - Meaning of blindness as defined in the law.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Meaning of blindness as defined in the law... INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.981 Meaning of blindness as defined in the law. We will consider you blind under the law for payment of...

  20. 20 CFR 416.981 - Meaning of blindness as defined in the law.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Meaning of blindness as defined in the law... INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.981 Meaning of blindness as defined in the law. We will consider you blind under the law for payment of...

  1. 20 CFR 416.981 - Meaning of blindness as defined in the law.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Meaning of blindness as defined in the law... INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.981 Meaning of blindness as defined in the law. We will consider you blind under the law for payment of...

  2. 20 CFR 416.981 - Meaning of blindness as defined in the law.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Meaning of blindness as defined in the law... INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.981 Meaning of blindness as defined in the law. We will consider you blind under the law for payment of...

  3. 20 CFR 416.981 - Meaning of blindness as defined in the law.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Meaning of blindness as defined in the law... INCOME FOR THE AGED, BLIND, AND DISABLED Determining Disability and Blindness Blindness § 416.981 Meaning of blindness as defined in the law. We will consider you blind under the law for payment of...

  4. Permanent Cortical Blindness After Bronchial Artery Embolization

    SciTech Connect

    Doorn, Colette S. van De Boo, Diederick W.; Weersink, Els J. M.; Delden, Otto M. van Reekers, Jim A. Lienden, Krijn P. van

    2013-12-15

    A 35-year-old female with a known medical history of cystic fibrosis was admitted to our institution for massive hemoptysis. CTA depicted a hypertrophied bronchial artery to the right upper lobe and showed signs of recent bleeding at that location. Bronchial artery embolization (BAE) was performed with gelfoam slurry, because pronounced shunting to the pulmonary artery was present. Immediately after BAE, the patient developed bilateral cortical blindness. Control angiography showed an initially not opacified anastomosis between the embolized bronchial artery and the right subclavian artery, near to the origin of the right vertebral artery. Cessation of outflow in the bronchial circulation reversed the flow through the anastomosis and allowed for spill of embolization material into the posterior circulation. Unfortunately the cortical blindness presented was permanent.

  5. Euro Banknote Recognition System for Blind People.

    PubMed

    Dunai Dunai, Larisa; Chillarón Pérez, Mónica; Peris-Fajarnés, Guillermo; Lengua Lengua, Ismael

    2017-01-20

    This paper presents the development of a portable system with the aim of allowing blind people to detect and recognize Euro banknotes. The developed device is based on a Raspberry Pi electronic instrument and a Raspberry Pi camera, Pi NoIR (No Infrared filter) dotted with additional infrared light, which is embedded into a pair of sunglasses that permit blind and visually impaired people to independently handle Euro banknotes, especially when receiving their cash back when shopping. The banknote detection is based on the modified Viola and Jones algorithms, while the banknote value recognition relies on the Speed Up Robust Features (SURF) technique. The accuracies of banknote detection and banknote value recognition are 84% and 97.5%, respectively.

  6. Euro Banknote Recognition System for Blind People

    PubMed Central

    Dunai Dunai, Larisa; Chillarón Pérez, Mónica; Peris-Fajarnés, Guillermo; Lengua Lengua, Ismael

    2017-01-01

    This paper presents the development of a portable system with the aim of allowing blind people to detect and recognize Euro banknotes. The developed device is based on a Raspberry Pi electronic instrument and a Raspberry Pi camera, Pi NoIR (No Infrared filter) dotted with additional infrared light, which is embedded into a pair of sunglasses that permit blind and visually impaired people to independently handle Euro banknotes, especially when receiving their cash back when shopping. The banknote detection is based on the modified Viola and Jones algorithms, while the banknote value recognition relies on the Speed Up Robust Features (SURF) technique. The accuracies of banknote detection and banknote value recognition are 84% and 97.5%, respectively. PMID:28117703

  7. Kalman filtering approach to blind equalization

    NASA Astrophysics Data System (ADS)

    Kutlu, Mehmet

    1993-12-01

    Digital communication systems suffer from the channel distortion problem which introduces errors due to intersymbol interference. The solution to this problem is provided by equalizers which use a training sequence to adapt to the channel. However in many cases in which a training sequence is unfeasible, the channel must be adapted blindly. Most of the blind equalization algorithms known so far have problems of convergence to local minima. Our intention is to offer an alternative approach by using extended Kalman filtering and hidden Markov models. They seem to yield more efficient algorithms which take the statistics of the transmitted sequence into consideration. The theoretical development of these new algorithms is discussed in this thesis. Also these algorithms have been simulated under different conditions. The results of simulations and comparisons with existing systems are provided. The models for simulations are presented as MATLAB codes.

  8. Sensing Structures Inspired by Blind Cave Fish

    NASA Astrophysics Data System (ADS)

    McConney, Michael E.; Chen, Nannan; Lu, David; Anderson, Kyle D.; Hu, Huan; Liu, Chang; Tsukruk, Vladimir V.

    2009-03-01

    Blind cave fish, with degenerated non-functioning eyes, have evolved to ``see'' their hydrodynamic environment by using the flow receptors of the lateral line system. The hair-cell receptors are encapsulated in a hydrogel-like material, called a cupula, which increases the sensitivity of the hair-cell receptors by coupling their motion to the surrounding flowing media. We characterized the viscoelastic properties and of blind cave fish cupulae by using colloidal-probe spectroscopy in fluid. A photo-patternable hydrogel with similar properties was developed to mimic the fish receptor coupling structure. Flow-based measurements indicated that the hydrogels enhance drag through increased surface area, but also inherent material properties. These bio-inspired structures endowed micro-fabricated flow sensors with sensitivities rivaling that of fish.

  9. Drawings from Gaia, a blind girl.

    PubMed

    Kennedy, John M

    2003-01-01

    Gaia, a totally blind girl, was asked to make raised-line drawings. Gaia's vision at best was peripheral. She draws out of interest, and has drawn since preschool with encouragement from her mother. She was asked to draw objects and scenes involving depth from a vantage point, eg a table from below, two cars (one behind the other), and two parallel rows of apples (receding from her, on a table top). Gaia represented space in her drawings using T-junctions for overlap, height in the picture plane, parallel projection, and inverse projection. That is, Gaia uses features of systems common in sighted children's drawings. The development of drawing in blind and sighted children may be similar in good measure because haptics provides access to many of the same spatial principles as vision.

  10. WHO celebrates triumph over river blindness.

    PubMed

    Ciment, J

    1999-10-23

    This article reports the success of WHO in eliminating onchocerciasis or river blindness in most of West Africa. The onchocerciasis control program was able to save 100,000 people at immediate risk of contracting the disease and prevented the infection of about 12 million children. About 1.25 million onchocercal infections have been resolved by the program. Moreover, removal of the threat of the disease has allowed people to farm 25 million hectares of fertile land capable of feeding 17 million people annually. The land was previously abandoned due to black fly infestations, the transmission vector of the disease. The control program, which was started 25 years ago, had successfully eliminated the disease after a partnership between the UN agency and Merck, the company that developed ivermectin. Ivermectin is the first drug against river blindness that could be dispensed widely without fear of serious side effects.

  11. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Dr. Marc Mauer, president of the National Federation of the Blind speaks at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  12. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    NASA astronaut Greg Johnson, left, speaks with Dr. Marc Mauer, president of the National Federation of the Blind, right, prior to a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  13. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    House Majority Leader U.S. Rep. Steny Hoyer, D-Md., speaks at a ceremony where senior NASA officials presented the National Federation for the Blind with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  14. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Dr. Marc Mauer, president of the National Federation of the Blind, at podium, speaks at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  15. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    House Majority Leader U.S. Rep. Steny Hoyer, D-Md., speaks at a ceremony where senior NASA officials presented the National Federation of the Blind with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  16. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Mark Riccobono, executive director of the Jernigan Institute of the National Federation of the Blind, at podium, delivers remarks at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  17. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    House Majority Leader U.S. Rep. Steny Hoyer, D-Md., smiles as he speaks to those in attendance at a ceremony where senior NASA officials presented the National Federation of the Blind with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  18. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    NASA Associate Administrator Chris Scolese, left, and Mark Riccobono, executive director of the Jernigan Institute of the National Federation of the Blind hold up a Braille enscribed award with two Louis Braille Bicentennial Silver Dollars at a ceremony where senior NASA officials presented the NFB with coins that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  19. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Derrick Tuff, right in wheelchair, and Kayla Weathers, standing left, deliver remarks at a ceremony where senior NASA officials presented the National Federation of the Blind with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Man standing at center is unidentified. Photo Credit: (NASA/Paul E. Alers)

  20. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Mark Riccobono, executive director of the Jernigan Institute of the National Federation of the Blind speaks at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  1. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Dr. Marc Mauer, president of the National Federation of the Blind accepts an award from William Gerstenmaier, Associate Administrator, Space Operations, NASA Headquarters at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  2. Quantum Key Distribution with Blind Polarization Bases

    NASA Astrophysics Data System (ADS)

    Kye, Won-Ho; Kim, Chil-Min; Kim, M. S.; Park, Young-Jai

    2005-07-01

    We propose a new quantum key distribution scheme that uses the blind polarization basis. In our scheme the sender and the receiver share key information by exchanging qubits with arbitrary polarization angles without basis reconciliation. As only random polarizations are transmitted, our protocol is secure even when a key is embedded in a not-so-weak coherent-state pulse. We show its security against the photon-number splitting attack and the impersonation attack.

  3. Dog Models for Blinding Inherited Retinal Dystrophies

    PubMed Central

    Komáromy, András M.

    2015-01-01

    Abstract Spontaneous canine models exist for several inherited retinal dystrophies. This review will summarize the models and indicate where they have been used in translational gene therapy trials. The RPE65 gene therapy trials to treat childhood blindness are a good example of how studies in dogs have contributed to therapy development. Outcomes in human clinical trials are compared and contrasted with the result of the preclinical dog trials. PMID:25671556

  4. Dog models for blinding inherited retinal dystrophies.

    PubMed

    Petersen-Jones, Simon M; Komáromy, András M

    2015-03-01

    Spontaneous canine models exist for several inherited retinal dystrophies. This review will summarize the models and indicate where they have been used in translational gene therapy trials. The RPE65 gene therapy trials to treat childhood blindness are a good example of how studies in dogs have contributed to therapy development. Outcomes in human clinical trials are compared and contrasted with the result of the preclinical dog trials.

  5. Measurement of Altitude in Blind Flying

    NASA Technical Reports Server (NTRS)

    Brombacher, W G

    1934-01-01

    In this note, instruments for measuring altitude and rate of change of altitude in blind flying and landing of aircraft and their performance are discussed. Of those indicating the altitude above ground level, the sonic altimeter is the most promising. Its present bulk, intermittent operation, and more or less unsatisfactory means of indication are serious drawbacks to its use. The sensitive type aneroid altimeter is also discussed and errors in flying at a pressure level and in landing are discussed in detail.

  6. Broadband Venetian Blind polarizer with dual vanes

    NASA Technical Reports Server (NTRS)

    Conroy, Bruce L.; Hoppe, Daniel J.; Imbriale, William A.

    1993-01-01

    During development of a Venetian Blind polarizer, high reflections and substantial pattern deformation were noted. Analysis showed that when the polarizer was illuminated slightly off axis, a degenerate mode was excited. This mode is resonant at the design center frequency, and was the cause of the problems. A design developed using dual vanes has been shown to be free of the problem. It also has greater bandwidth.

  7. Broadband Venetian Blind polarizer with dual vanes

    NASA Technical Reports Server (NTRS)

    Conroy, Bruce L.; Hoppe, Daniel J.; Imbriale, William A.

    1993-01-01

    During development of a Venetian Blind polarizer, high reflections and substantial pattern deformation were noted. Analysis showed that when the polarizer was illuminated slightly off axis, a degenerate mode was excited. This mode is resonant at the design center frequency, and was the cause of the problems. A design developed using dual vanes has been shown to be free of the problem. It also has greater bandwidth.

  8. Blindness and intranasal endoscopic ethmoidectomy: prevention and management.

    PubMed

    Stankiewicz, J A

    1989-09-01

    Blindness is one of the major complications that can occur during and after intranasal ethmoidectomy. Two mechanisms for blindness are apparent: (1) direct injury to the optic nerve and (2) retrobulbar (orbital) hematoma, which increases orbital pressure and compromises vascular supply and drainage to and from the eye. While several publications have discussed the management of blindness from a delayed operative vantage point, no publication has discussed the immediate management of blindness from intraoperative or immediate postoperative occurrence, stressing specific medical and surgical treatment. A review of the literature and the author's personal experience will be used as a basis to discuss the prevention and management of blindness during endoscopic intranasal ethmoidectomy. Case studies will be used to illustrate methods for prevention and management of blindness. If treated aggressively, blindness associated with retrobulbar hematoma can be reversed medically.

  9. A Completely Blind Video Integrity Oracle.

    PubMed

    Mittal, Anish; Saad, Michele A; Bovik, Alan C

    2016-01-01

    Considerable progress has been made toward developing still picture perceptual quality analyzers that do not require any reference picture and that are not trained on human opinion scores of distorted images. However, there do not yet exist any such completely blind video quality assessment (VQA) models. Here, we attempt to bridge this gap by developing a new VQA model called the video intrinsic integrity and distortion evaluation oracle (VIIDEO). The new model does not require the use of any additional information other than the video being quality evaluated. VIIDEO embodies models of intrinsic statistical regularities that are observed in natural vidoes, which are used to quantify disturbances introduced due to distortions. An algorithm derived from the VIIDEO model is thereby able to predict the quality of distorted videos without any external knowledge about the pristine source, anticipated distortions, or human judgments of video quality. Even with such a paucity of information, we are able to show that the VIIDEO algorithm performs much better than the legacy full reference quality measure MSE on the LIVE VQA database and delivers performance comparable with a leading human judgment trained blind VQA model. We believe that the VIIDEO algorithm is a significant step toward making real-time monitoring of completely blind video quality possible.

  10. Blind deconvolution and source separation in acoustics

    NASA Astrophysics Data System (ADS)

    Sibul, Leon H.; Roan, Michael J.; Coviello, Christian M.

    2005-09-01

    Blind deconvolution (BDC) and blind source separation (BSS) are active research topics with many important applications in acoustics. The goal of deconvolution is to recover original input signal from the output of a convolution filter. In blind deconvolution details of the convolution filter and input signals are not known. The fundamental assumption in BDC is that the input signal is a non-Gaussian stochastic process. A topic closely related to BDC is BSS. BSS is a process that is an inverse operation to a mixing process. In BSS it is assumed that inputs to the mixing systems are statistically independent stochastic processes, where only one input may be Gaussian, others must be non-Gaussian. Standard criterion functions for BDC and BSS are reviewed. Limitations of the second-order statistics and need for higher-order statistics (HOS) or information theoretic criteria that lead to nonlinear optimization algorithms are pointed out. Advantages of various information theoretic criteria for BDC and BSS are discussed. Because gradients of these criteria are nonlinear, resulting optimization algorithms are nonlinear. Linear and non-linear algorithms for BDC and BSS are examined. [Work supported by ONR Codes 321US and 333.

  11. Poverty and blindness in Pakistan: results from the Pakistan national blindness and visual impairment survey.

    PubMed

    Gilbert, Clare E; Shah, S P; Jadoon, M Z; Bourne, R; Dineen, B; Khan, M A; Johnson, G J; Khan, M D

    2008-01-05

    To explore the association between blindness and deprivation in a nationally representative sample of adults in Pakistan. Cross sectional population based survey. 221 rural and urban clusters selected randomly throughout Pakistan. Nationally representative sample of 16 507 adults aged 30 or above (95.3% response rate). Associations between visual impairment and poverty assessed by a cluster level deprivation index and a household level poverty indicator; prevalence and causes of blindness; measures of the rate of uptake and quality of eye care services. 561 blind participants (<3/60 in the better eye) were identified during the survey. Clusters in urban Sindh province were the most affluent, whereas rural areas in Balochistan were the poorest. The prevalence of blindness in adults living in affluent clusters was 2.2%, compared with 3.7% in medium clusters and 3.9% in poor clusters (P<0.001 for affluent v poor). The highest prevalence of blindness was found in rural Balochistan (5.2%). The prevalence of total blindness (bilateral no light perception) was more than three times higher in poor clusters than in affluent clusters (0.24% v 0.07%, P<0.001). The prevalences of blindness caused by cataract, glaucoma, and corneal opacity were lower in affluent clusters and households. Reflecting access to eye care services, cataract surgical coverage was higher in affluent clusters (80.6%) than in medium (76.8%) and poor areas (75.1%). Intraocular lens implantation rates were significantly lower in participants from poorer households. 10.2% of adults living in affluent clusters presented to the examination station wearing spectacles, compared with 6.7% in medium clusters and 4.4% in poor cluster areas. Spectacle coverage in affluent areas was more than double that in poor clusters (23.5% v 11.1%, P<0.001). Blindness is associated with poverty in Pakistan; lower access to eye care services was one contributory factor. To reduce blindness, strategies targeting poor people will

  12. The spatiotopic 'visual' cortex of the blind

    NASA Astrophysics Data System (ADS)

    Likova, Lora

    2012-03-01

    Visual cortex activity in the blind has been shown in sensory tasks. Can it be activated in memory tasks? If so, are inherent features of its organization meaningfully employed? Our recent results in short-term blindfolded subjects imply that human primary visual cortex (V1) may operate as a modality-independent 'sketchpad' for working memory (Likova, 2010a). Interestingly, the spread of the V1 activation approximately corresponded to the spatial extent of the images in terms of their angle of projection to the subject. We now raise the questions of whether under long-term visual deprivation V1 is also employed in non-visual memory task, in particular in congenitally blind individuals, who have never had visual stimulation to guide the development of the visual area organization, and whether such spatial organization is still valid for the same paradigm that was used in blindfolded individuals. The outcome has implications for an emerging reconceptualization of the principles of brain architecture and its reorganization under sensory deprivation. Methods: We used a novel fMRI drawing paradigm in congenitally and late-onset blind, compared with sighted and blindfolded subjects in three conditions of 20s duration, separated by 20s rest-intervals, (i) Tactile Exploration: raised-line images explored and memorized; (ii) Tactile Memory Drawing: drawing the explored image from memory; (iii) Scribble: mindless drawing movements with no memory component. Results and Conclusions: V1 was strongly activated for Tactile Memory Drawing and Tactile Exploration in these totally blind subjects. Remarkably, after training, even in the memory task, the mapping of V1 activation largely corresponded to the angular projection of the tactile stimuli relative to the ego-center (i.e., the effective visual angle at the head); beyond this projective boundary, peripheral V1 signals were dramatically reduced or even suppressed. The matching extent of the activation in the congenitally blind

  13. Blindness and the age of enlightenment: Diderot's letter on the blind.

    PubMed

    Margo, Curtis E; Harman, Lynn E; Smith, Don B

    2013-01-01

    Several months after anonymously publishing an essay in 1749 with the title "Letter on the Blind for the Use of Those Who Can See," the chief editor of the French Encyclopédie was arrested and taken to the prison fortress of Vincennes just east of Paris, France. The correctly assumed author, Denis Diderot, was 35 years old and had not yet left his imprint on the Age of Enlightenment. His letter, which recounted the life of Nicolas Saunderson, a blind mathematician, was intended to advance secular empiricism and disparage the religiously tinged rationalism put forward by Rene Descartes. The letter's discussion of sensory perception in men born blind dismissed the supposed primacy of visual imagery in abstract thinking. The essay did little to resolve any philosophical controversy, but it marked a turning point in Western attitudes toward visual disability.

  14. When Emotion Blinds: A Spatiotemporal Competition Account of Emotion-Induced Blindness

    PubMed Central

    Wang, Lingling; Kennedy, Briana L.; Most, Steven B.

    2012-01-01

    Emotional visual scenes are such powerful attractors of attention that they can disrupt perception of other stimuli that appear soon afterward, an effect known as emotion-induced blindness. What mechanisms underlie this impact of emotion on perception? Evidence suggests that emotion-induced blindness may be distinguishable from closely related phenomena such as the orienting of spatial attention to emotional stimuli or the central resource bottlenecks commonly associated with the attentional blink. Instead, we suggest that emotion-induced blindness reflects relatively early competition between targets and emotional distractors, where spontaneous prioritization of emotional stimuli leads to suppression of competing perceptual representations potentially linked to an overlapping point in time and space. PMID:23162497

  15. Parameter estimation for blind and non-blind deblurring using residual whiteness measures.

    PubMed

    Almeida, Mariana S C; Figueiredo, Mario A T

    2013-07-01

    Image deblurring (ID) is an ill-posed problem typically addressed by using regularization, or prior knowledge, on the unknown image (and also on the blur operator, in the blind case). ID is often formulated as an optimization problem, where the objective function includes a data term encouraging the estimated image (and blur, in blind ID) to explain the observed data well (typically, the squared norm of a residual) plus a regularizer that penalizes solutions deemed undesirable. The performance of this approach depends critically (among other things) on the relative weight of the regularizer (the regularization parameter) and on the number of iterations of the algorithm used to address the optimization problem. In this paper, we propose new criteria for adjusting the regularization parameter and/or the number of iterations of ID algorithms. The rationale is that if the recovered image (and blur, in blind ID) is well estimated, the residual image is spectrally white; contrarily, a poorly deblurred image typically exhibits structured artifacts (e.g., ringing, oversmoothness), yielding residuals that are not spectrally white. The proposed criterion is particularly well suited to a recent blind ID algorithm that uses continuation, i.e., slowly decreases the regularization parameter along the iterations; in this case, choosing this parameter and deciding when to stop are one and the same thing. Our experiments show that the proposed whiteness-based criteria yield improvements in SNR, on average, only 0.15 dB below those obtained by (clairvoyantly) stopping the algorithm at the best SNR. We also illustrate the proposed criteria on non-blind ID, reporting results that are competitive with state-of-the-art criteria (such as Monte Carlo-based GSURE and projected SURE), which, however, are not applicable for blind ID.

  16. Attack and improvements of fair quantum blind signature schemes

    NASA Astrophysics Data System (ADS)

    Zou, Xiangfu; Qiu, Daowen

    2013-06-01

    Blind signature schemes allow users to obtain the signature of a message while the signer learns neither the message nor the resulting signature. Therefore, blind signatures have been used to realize cryptographic protocols providing the anonymity of some participants, such as: secure electronic payment systems and electronic voting systems. A fair blind signature is a form of blind signature which the anonymity could be removed with the help of a trusted entity, when this is required for legal reasons. Recently, a fair quantum blind signature scheme was proposed and thought to be safe. In this paper, we first point out that there exists a new attack on fair quantum blind signature schemes. The attack shows that, if any sender has intercepted any valid signature, he (she) can counterfeit a valid signature for any message and can not be traced by the counterfeited blind signature. Then, we construct a fair quantum blind signature scheme by improved the existed one. The proposed fair quantum blind signature scheme can resist the preceding attack. Furthermore, we demonstrate the security of the proposed fair quantum blind signature scheme and compare it with the other one.

  17. Congenital abnormalities of the urogenital tract: the clue is in the cord?

    PubMed

    Daoub, Ahmed; Drake, Thomas M

    2014-12-02

    Congenital abnormalities of the female urogenital tract are not uncommon, with an estimated incidence of 2-4% across the female population. Within this population, up to 40% will have associated renal tract abnormalities. A previously well 12-year-old girl presented to the emergency department with abdominal pain, vomiting and a palpable pelvic mass. Ultrasound and MR scans were performed. The imaging revealed a didelphys uterus, an obstructed hemivagina and ipsilateral renal agenesis, characteristic of Herlyn-Werner-Wunderlich syndrome. The patient was noted at birth to have a single umbilical artery, which is associated with an increased risk of congenital abnormalities and useful information for the early identification of abnormalities that have implications for renal function and future fertility. 2014 BMJ Publishing Group Ltd.

  18. Rhodopsin bleaching signals in essential night blindness

    PubMed Central

    Alpern, M.; Holland, M. G.; Ohba, N.

    1972-01-01

    1. The dark-adaptation curves of two subjects with essential night blindness revealed no evidence for functioning rod vision. Cone vision was normal. 2. The photopupillomotor dark adaptation, and flash intensity response amplitude curves on one of these subjects confirmed the absence of rod function. 3. However, there is the normal amount of rhodopsin in their rods with normal kinetics. 4. Cone pigment kinetics are also nearly normal. After a full bleach, log threshold elevation of the foveal cones is linearly related to pigment regeneration. The constant of proportionality is about 3·0 as it is in the normal retina. 5. After a full rhodopsin bleach, the contralateral pupil size recovered its full dark value along a curve which followed the regeneration of rhodopsin. 6. The results in (5) are identical to those previously found on normal subjects. 7. With the exception of a very small response attributed to the contribution of cones, no significant changes in pupil size were evoked by uniform ganzfeld steady backgrounds until the intensity of retinal illuminance was so high that appreciable rhodopsin was bleached. This contrast to the changes evoked by weak steady backgrounds in the normal eye. 8. Therefore, rod bleaching signals are normal in such retinas but rod signals evoked by real lights are not functional. This supports Rushton's concept as to how bleaching signals influence retinal sensitivity as opposed to the view of Barlow. 9. The defect in essential night blindness very probably involves the rod automatic gain control, but because of (4) the cone gain control must be normal. 10. Therefore, rod and cone gain control mechanisms must be independent in these night blind retinas and, by analogy, in the normal retina as well. PMID:4538549

  19. No training blind image quality assessment

    NASA Astrophysics Data System (ADS)

    Chu, Ying; Mou, Xuanqin; Ji, Zhen

    2014-03-01

    State of the art blind image quality assessment (IQA) methods generally extract perceptual features from the training images, and send them into support vector machine (SVM) to learn the regression model, which could be used to further predict the quality scores of the testing images. However, these methods need complicated training and learning, and the evaluation results are sensitive to image contents and learning strategies. In this paper, two novel blind IQA metrics without training and learning are firstly proposed. The new methods extract perceptual features, i.e., the shape consistency of conditional histograms, from the joint histograms of neighboring divisive normalization transform coefficients of distorted images, and then compare the length attribute of the extracted features with that of the reference images and degraded images in the LIVE database. For the first method, a cluster center is found in the feature attribute space of the natural reference images, and the distance between the feature attribute of the distorted image and the cluster center is adopted as the quality label. The second method utilizes the feature attributes and subjective scores of all the images in the LIVE database to construct a dictionary, and the final quality score is calculated by interpolating the subjective scores of nearby words in the dictionary. Unlike the traditional SVM based blind IQA methods, the proposed metrics have explicit expressions, which reflect the relationships of the perceptual features and the image quality well. Experiment results in the publicly available databases such as LIVE, CSIQ and TID2008 had shown the effectiveness of the proposed methods, and the performances are fairly acceptable.

  20. PARENT Quick Blind Round-Robin Test Report

    SciTech Connect

    Braatz, Brett G.; Heasler, Patrick G.; Meyer, Ryan M.

    2014-09-30

    The U.S. Nuclear Regulatory Commission has established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) whose goal is to investigate the effectiveness of current and novel nondestructive examination procedures and techniques to find flaws in nickel-alloy welds and base materials. This is to be done by conducting a series of open and blind international round-robin tests on a set of piping components that include large-bore dissimilar metal welds, small-bore dissimilar metal welds, and bottom-mounted instrumentation penetration welds. The blind testing is being conducted in two segments, one is called Quick-Blind and the other is called Blind. The Quick-Blind testing and destructive analysis of the test blocks has been completed. This report describes the four Quick-Blind test blocks used, summarizes their destructive analysis, gives an overview of the nondestructive evaluation (NDE) techniques applied, provides an analysis inspection data, and presents the conclusions drawn.

  1. Reflective insulating blinds for windows and the like

    DOEpatents

    Barnes, P.R.; Shapira, H.B.

    1979-12-07

    Energy-conserving window blinds are provided. The blinds are fabricated from coupled and adjustable slats, each slat having an insulation layer and a reflective surface to face outwardly when the blinds are closed. A range of desired light and air transmission may be selected with the reflective surfaces of the slats adapted to direct sunlight upward toward the ceiling when the blinds are open. When the blinds are closed, the insulation of the slats reduces the heat loss or gain produced by the windows. If desired, the reflective surfaces of the slats may be concave. The edges of the slats are designed to seal against adjacent slats when the blinds are closed to ensure minimum air flow between slats.

  2. Reflective insulating blinds for windows and the like

    DOEpatents

    Barnes, Paul R.; Shapira, Hanna B.

    1981-01-01

    Energy-conserving window blinds are provided. The blinds are fabricated from coupled and adjustable slats, each slat having an insulation layer and a reflective surface to face outwardly when the blinds are closed. A range of desired light and air transmission may be selected with the reflective surfaces of the slats adapted to direct sunlight upward toward the ceiling when the blinds are open. When the blinds are closed, the insulation of the slats reduces the heat loss or gain produced by the windows. If desired, the reflective surfaces of the slats may be concave. The edges of the slats are designed to seal against adjacent slats when the blinds are closed to ensure minimum air flow between slats.

  3. Temporal arteritis with scalp ulceration and blindness.

    PubMed

    Gkalpakiotis, Spyridon; Arenberger, Petr; Sach, Josef; Arenbergerova, Monika

    2011-01-01

    Temporal arteritis or giant cell arteritis is a systemic granulomatous vasculitis of medium and large-sized arteries, most frequently involving the temporal artery. It presents with headache, fever, elevated erythrocyte sedimentation rate and anemia. If untreated, complications like ischemic optic neuritis may even lead to blindness. Although very rare, scalp necrosis and ulcerations are the most common dermatologic findings. An 85-year-old woman presented with a two-month history of bilateral scalp ulcerations, followed by permanent loss of vision in the left eye due to the delay in diagnosing temporal arteritis. © The Authors • Journal compilation © Blackwell Verlag GmbH, Berlin.

  4. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    Mark Riccobono, executive director of the Jernigan Institute of the National Federation of the Blind, right, accepts an award from Dr. Joyce Winterton, Assistant Administrator, Office of Education, NASA Headquarters, center, and Ken Silberman, from Goddard Space Flight Center, at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  5. National Federation of the Blind Braille Coin

    NASA Image and Video Library

    2009-07-30

    House Majority Leader U.S. Rep. Steny Hoyer, D-Md., left, holds up an award presented to him by Mark Riccobono, executive director of the Jernigan Institute of the National Federation of the Blind at a ceremony where senior NASA officials presented the NFB with two Louis Braille Bicentennial Silver Dollars that flew on Space Shuttle Atlantis' mission (STS-125) to the Hubble Space Telescope in May 2009, Friday evening, July 31, 2009, at the Capitol Visitors Center in Washington. Photo Credit: (NASA/Paul E. Alers)

  6. Psychiatric and behavioral correlates of factitious blindness.

    PubMed

    Feldman, Marc D; Eisendrath, Stuart J; Tyerman, Mike

    2008-01-01

    In factitious disorder, an individual feigns, exaggerates, or actually self-induces physical or psychiatric illness to achieve ends such as mobilizing care and concern, ventilating aggression, diminishing guilty feelings, or gratifying dependency wishes. We present 2 new cases of factitious binocular blindness, which has rarely been reported but readily illustrates the dramatic range of factitious illness behaviors. Psychiatric and behavioral correlates culled from these cases include extravagant claims about the impairment and ludicrous claims for nonvisual sensory abilities. These patients typically refuse psychiatric care, but earlier detection can help abort the illness deceptions and forestall iatrogenic complications.

  7. The chemistry of John Dalton's color blindness.

    PubMed

    Hunt, D M; Dulai, K S; Bowmaker, J K; Mollon, J D

    1995-02-17

    John Dalton described his own color blindness in 1794. In common with his brother, he confused scarlet with green and pink with blue. Dalton supposed that his vitreous humor was tinted blue, selectively absorbing longer wavelengths. He instructed that his eyes should be examined after his death, but the examination revealed that the humors were perfectly clear. In experiments presented here, DNA extracted from his preserved eye tissue showed that Dalton was a deuteranope, lacking the middlewave photopigment of the retina. This diagnosis is shown to be compatible with the historical record of his phenotype, although it contradicts Thomas Young's belief that Dalton was a protanope.

  8. Change Blindness in Information Visualization: a Case Study

    SciTech Connect

    Nowell, Lucy T.; Hetzler, Elizabeth G.; Tanasse, Ted E.

    2001-08-20

    Change blindness occurs when people do not notice changes in visible elements of a scene. In using an information visualization system to compare document collection subsets partitioned by their time-stamps, change blindness makes it impossible for users to recognize even very major changes, let alone minor ones. We describe theories from cognitive science that account for the change blindness phenomenon, as well as solutions developed for two visual analysis tools, the SPIRE Galaxies visualization and the SPIRE ThemeView?.

  9. Sixth blind test of organic crystal-structure prediction methods.

    PubMed

    Groom, Colin R; Reilly, Anthony M

    2014-08-01

    Over the past 15 years progress in predicting crystal structures of small organic molecules has been charted by a series of blind tests hosted by the Cambridge Crystallographic Data Centre. This letter announces a sixth blind test to take place between September 2014 and August 2015, giving details of the target systems and the revised procedure. We hope that as many methods as possible will be assessed and benchmarked in this new blind test.

  10. Blind Image Inpainting Based on TV Model and Edge Detection

    NASA Astrophysics Data System (ADS)

    Wang, Xin-Yu; Deng, Liang-Jian

    Blind image inpainting is an approach to estimate the original image, when there is no or little knowledge of the degraded process. In this paper, the algorithm of blind image inpainting is based on edge detection methods to generate one inpainting mask H automatically. And then we combine the inpainting mask H with a TV model to get image blind inpainted. Experiment results demonstrate that the proposed algorithms is effective with application to both the synthetic and real-world images.

  11. [Change to "prevention of the avoidable blindness and visual impairment" from "prevention of blindness"].

    PubMed

    Zhao, Jialiang

    2015-07-01

    The formulation on the eye health by WHO had an obvious change in recent years. Before 2006, WHO and WHA solutions clearly put forward the prevention of blindness. After 2006, WHO and WHA solutions on the eye health emphasized the elimination of the avoidable blindness and visual impairment. This change extends the scope of eye health, reflects the important progress on the global eye health, and also reflects the social progress and the increase to the need on eye health by the public. This change conforms to the actual situation in China. It is necessary to adopt elimination of the avoidable blindness and visual impairment as the priorities in eye health in making the 13th national plan of blindness prevention. This change is not merely a matter of wording, but also a great change in the working content in eye health. The change demonstrates the deep development on the eye health, and may benefit more people and promote the further development of eye health and ophthalmology in China.

  12. Color-Blind Racism, Color-Blind Theology, and Church Practices

    ERIC Educational Resources Information Center

    Hearn, Mark

    2009-01-01

    Color-blind racism develops when persons ignore color in people and see them simply as individuals. As persons of color in racialized societies such as the United States are unequally treated on account of their color, the issue becomes a matter of faith and religious experience as religious leaders and educators, who disregard color, overlook…

  13. Accuracy assessment of blind and semi-blind restoration methods for hyperspectral images

    NASA Astrophysics Data System (ADS)

    Zhang, Mo; Vozel, Benoit; Chehdi, Kacem; Uss, Mykhail; Abramov, Sergey; Lukin, Vladimir

    2016-10-01

    Hyperspectral images acquired by remote sensing systems are generally degraded by noise and can be sometimes more severely degraded by blur. When no knowledge is available about the degradations present or the original image, blind restoration methods must be considered. Otherwise, when a partial information is needed, semi-blind restoration methods can be considered. Numerous semi-blind and quite advanced methods are available in the literature. So to get better insights and feedback on the applicability and potential efficiency of a representative set of four semi-blind methods recently proposed, we have performed a comparative study of these methods in objective terms of blur filter and original image error estimation accuracy. In particular, we have paid special attention to the accurate recovering in the spectral dimension of original spectral signatures. We have analyzed peculiarities and factors restricting the applicability of these methods. Our tests are performed on a synthetic hyperspectral image, degraded with various synthetic blurs (out-of-focus, gaussian, motion) and with signal independent noise of typical levels such as those encountered in real hyperspectral images. This synthetic image has been built from various samples from classified areas of a real-life hyperspectral image, in order to benefit from realistic reference spectral signatures to recover after synthetic degradation. Conclusions, practical recommendations and perspectives are drawn from the results experimentally obtained.

  14. Advice from Blind Teachers on How to Teach Statistics to Blind Students

    ERIC Educational Resources Information Center

    Godfrey, A. Jonathan R.; Loots, M. Theodor

    2015-01-01

    Blind students are bound to make up a very small part of the population most university lecturers will encounter during their careers. Research to date shows that good communication between staff and student improves the chances of a successful outcome for both parties. The research does show, however, that the exercise seems to be one of…

  15. Color-Blind Racism, Color-Blind Theology, and Church Practices

    ERIC Educational Resources Information Center

    Hearn, Mark

    2009-01-01

    Color-blind racism develops when persons ignore color in people and see them simply as individuals. As persons of color in racialized societies such as the United States are unequally treated on account of their color, the issue becomes a matter of faith and religious experience as religious leaders and educators, who disregard color, overlook…

  16. De-Institutionalizing for the Blind: Life Learning Center for the Blind Retarded, Boston

    ERIC Educational Resources Information Center

    Stephens, Suzanne

    1978-01-01

    A projected learning center in an urban area will be a transitional home, part of an evolving effort to "de-institutionalize" the living environment of the blind and train them to become self-sufficient enough to lead normal lives. (Author/MLF)

  17. The Herlyn-Werner-Wunderlich Syndrome – A Case Report with Radiological Review

    PubMed Central

    Khaladkar, Sanjay Mhalasakant; Kamal, Vigyat; Kamal, Anubhav; Kondapavuluri, Sushen Kumar

    2016-01-01

    Summary Background HWW syndrome is a very rare congenital anomaly of urogenital tract involving Mullerian ducts and mesonephric ducts. It is characterised by a triad of symptoms - uterus didelphys, obstructed hemivagina and ipsilateral renal agenesis. It can be classified based on a completely or incompletely obstructed hemivagina. It presents soon after menarche or shows delayed presentation depending on the type. It can exhibit acute pelvic pain shortly after menarche and may show non-specific and variable symptoms with resultant delay in diagnosis. The most common presentation is pain and dysmenorrhea, and pain and abdominal mass in the lower abdomen secondary to haematocolpos and/or haematometra. Case Report Presentation of a clinical case of a 13-year-old patient with HWW syndrome presenting with regular menses, dysmenorrhea and painful lump in hypogastric region on the left side of midline. We described the role of imaging modalities in diagnosis of the Herlyn-Werner-Wunderlich syndrome with a review of literature. USG and MRI showed left renal agenesis with compensatory hypertrophy of the right kidney, uterus didelphys with haematometra and haematocervix in the left uterus with evidence of blood in a dilated retort-shaped left fallopian tube and a normal right uterus. The unique feature of our case is haematometra and haematocervix with cervical and vaginal atresia found on the left side (classification 1.2) with associated left renal agenesis. Conclusions HWW syndrome can present early or late, depending on the type. In patients with uterine and vaginal abnormalities, a work-up for associated renal anomalies should be performed. Early intervention is needed to reduce the risk of endometriosis and infertility. PMID:28058067

  18. Causes of blindness and visual impairment in Pakistan. The Pakistan national blindness and visual impairment survey

    PubMed Central

    Dineen, B; Bourne, R R A; Jadoon, Z; Shah, S P; Khan, M A; Foster, A; Gilbert, C E; Khan, M D

    2007-01-01

    Objective To determine the causes of blindness and visual impairment in adults (⩾30 years old) in Pakistan, and to explore socio‐demographic variations in cause. Methods A multi‐stage, stratified, cluster random sampling survey was used to select a nationally representative sample of adults. Each subject was interviewed, had their visual acuity measured and underwent autorefraction and fundus/optic disc examination. Those with a visual acuity of <6/12 in either eye underwent a more detailed ophthalmic examination. Causes of visual impairment were classified according to the accepted World Health Organization (WHO) methodology. An exploration of demographic variables was conducted using regression modeling. Results A sample of 16 507 adults (95.5% of those enumerated) was examined. Cataract was the most common cause of blindness (51.5%; defined as <3/60 in the better eye on presentation) followed by corneal opacity (11.8%), uncorrected aphakia (8.6%) and glaucoma (7.1%). Posterior capsular opacification accounted for 3.6% of blindness. Among the moderately visually impaired (<6/18 to ⩾6/60), refractive error was the most common cause (43%), followed by cataract (42%). Refractive error as a cause of severe visual impairment/blindness was significantly higher in rural dwellers than in urban dwellers (odds ratio (OR) 3.5, 95% CI 1.1 to 11.7). Significant provincial differences were also identified. Overall we estimate that 85.5% of causes were avoidable and that 904 000 adults in Pakistan have cataract (<6/60) requiring surgical intervention. Conclusions This comprehensive survey provides reliable estimates of the causes of blindness and visual impairment in Pakistan. Despite expanded surgical services, cataract still accounts for over half of the cases of blindness in Pakistan. One in eight blind adults has visual loss from sequelae of cataract surgery. Services for refractive errors need to be further expanded and integrated into eye care services

  19. Fuzzy-based simulation of real color blindness.

    PubMed

    Lee, Jinmi; dos Santos, Wellington P

    2010-01-01

    About 8% of men are affected by color blindness. That population is at a disadvantage since they cannot perceive a substantial amount of the visual information. This work presents two computational tools developed to assist color blind people. The first one tests color blindness and assess its severity. The second tool is based on Fuzzy Logic, and implements a method proposed to simulate real red and green color blindness in order to generate synthetic cases of color vision disturbance in a statistically significant amount. Our purpose is to develop correction tools and obtain a deeper understanding of the accessibility problems faced by people with chromatic visual impairment.

  20. Red-green colour blindness in Singaporean children.

    PubMed

    Chia, Audrey; Gazzard, Gus; Tong, Louis; Zhang, Xiaoe; Sim, Ee-Ling; Fong, Allan; Mei Saw, Seang

    2008-07-01

    X-linked red-green colour blindness is the most common form of colour blindness. Various studies suggest that, worldwide, 2-8% of men are afflicted with this condition. The purpose of this study is to determine the prevalence of red-green colour blindness in Singaporean schoolchildren. A total of 1249 children aged 13-15 years were screened using the Ishihara 24-plate edition book during the School Cohort study of the Risk factors for Myopia visit. A total of 1210 children (96.8%) managed to correctly identify at least 13 of the initial 15 plates and were deemed to have normal colour vision.Thirty-three children (32 boys, one girl) were only able to identify nine or less plates and were considered to be colour blind. Overall, 5.4% (95% confidence interval 3%, 7%) of Chinese, 4.9% (1%, 9%) of Malay and 4.9% (2%, 11%) of Indian boys were colour blind (P = 0.97). Classification plates 16-17 were useful in determining deutran or protan tendencies in only 14 (43%) of the 33 children identified as being colour blind. 5.3% of boys and 0.2% of girls were found to be colour blind in this Singapore-based study. Although the Ishihara test proved useful in identifying colour-blind children, other tests are required to accurately classify the types of red-green colour blindness in these children.