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Sample records for duplex-doppler colour echography

  1. The duplex-Doppler colour echography of the scrotum and testicles in adults and boys. III. Assessment of chronic scrotal pathology; Ecografia duplex-Doppler color del escroto y el testiculo en el adulto y el nino. III. Valoracion de la patologia escrotal cronica

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    Rangel-Villalobos, E.; Benjumeda, A.; Jimenez-Castellanos, R.; Linares, A.; Blanco, A [Hospital Universitario Virgen Macarena. Sevilla (Spain)

    1999-07-01

    To show the most outstanding findings from the chronic scrotal pathology of adults and boys, determining the benefits of the Doppler echography in the diagnostical valuation of the different cases analysed. 40 patients (19 adults and 21 boys) with chronic scrotal symptomatology were examined using a B mode echography followed by a colour duplex-Doppler (CDD) echography with a lineal 7.5 MHz transducer. We compared the findings obtained with those corresponding to the contralateral testicle and, depending on the pathology, we co-related them with surgery, pathologic anatomy or clinical-echograph evolution. The pathology found was very varied, it was distributed into: varicoceles (12), testicle tumours (9), extra-testicle tumours (4) and miscellaneous pathology (13). Two patients showed no changes, currently remaining asymptomatic. The treatment was surgical in 28 (70%) of the patients and traditional in the others. The B mode echography played a fundamental role in the diagnosis of chronic scrotal pathology, which in the majority of the cases was definitive, being completed with the application of the Doppler echograph to analyse the vascular condition of the lesions and the anatomical structures. The diagnosis utility of the CDD echograph in chronic scrotal pathology is controversial, it is not specific for testicle tumors, it is very useful for variocele and complementary, tp the B mode echograph for miscellaneous pathology. (Author) 31 refs.

  2. The duplex-Doppler colour echography of the scrotum and testicles in adults and boys. II. the contribution of the urgent study of acute scrotum symptoms; Ecografia duples-Doppler color del escroto y el testiculo en el adulto y el nino. II. Aportacion al estudio urgente del escroto agudo

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    Rangel-Villalobos, E.; Jimenez-Castellanos, R.; Bustos, C.; Linares, A.; Gonzalez-Prada, F. [Hospital Universitario Virgen Macarena. Sevilla (Spain)

    1999-07-01

    To analyse the findings, contributions and limitations of the Doppler echography for the urgent study of acute scrotum symptoms, both in adults and in boys. 60 patients (22 adults and 38 boys) with acute scrotal symptomatology were examined using B mode echography, followed by a colour duplex-Doppler (CDD) echography with a lineal 7.5 MHz transducer. We compared the findings obtained with those of the healthy contralateral testicle and with surgery or clinical-echographical evolution. The most common pathology was inflammation (27%) followed by ischemic (24%) and traumatic (17%). 12% of the patients had miscellaneous conditions. To conclude, in 20% of the cases the B mode and the Doppler examination was normal, the symptoms were resolved spontaneously. After carrying out the CDD only 14 (23%) of the cases needed immediate surgery and 3 (5%) delayed surgery, the remaining 43 (72%) patients responded to the traditional treatment. The CDD allows for a safe, quick and harmless diagnosis in practically all the acute scrotum cases, for both adults and boys. Its limitations in pre-puberty patients or in cases that were atypical are overcome when put in the hands of an expert radiologist, as they need a longer exploration time and suitable Doppler equipment. The main contribution to the urgent diagnosis of acute scrotum symptoms is that it accurately establishes which patients should be chosen for immediate surgery. (Author) 33 refs.

  3. Renal duplex Doppler ultrasound findings in diabetics

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    Shim, Hyang Yee; Kim, Young Geun; Kook, Cheol Keu; Yoon, Chong Hyun; Lee, Shin Hyung; Lee, Chang Joon [National Medical Center, Seoul (Korea, Republic of)

    1993-12-15

    The correlation between clinical-laboratory findings and renal duplex Doppler ultrasound findings was studied in 45 patients with diabetes mellitus to see the role of duplex Doppler ultrasound in the detection of diabetic nephropathy. The resistive indices in patients with elevated serum creatinine, BUN, proteinuria, and systolic blood pressure levels were statistically significantly higher than those in patients with normal levels (p<0.05). Also resistive indics in patients with retinopathy were higher than that in patients without retinopathy (p<0.05). But the ultrasound morphologic changes of kidney such as renal length, cortical eye-catching, and corticomedullarycontrast were not well correlated with clinical-laboratory data and resistive index. The resistive index of the kidney in conjunction with clinical-laboratory data in diabetics may be helpful in the evaluation of diabetic nephropathy

  4. Transcranial duplex doppler ultrasonography in dogs with hydrocephalus Ultrassonografia duplex Doppler transcraniana em cães com hidrocefalia

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    C.F. Carvalho

    2010-02-01

    Full Text Available Transcranial duplex Doppler ultrasound was performed in 32 conscious dogs presenting ventriculomegaly detected in B-mode, obtaining measures of lateral ventricles and resistance parameters of main cerebral arteries before and after 30 days of clinical treatment. The animals were distributed divided in two groups: group 1, dogs that presented remission or decrease of the neurological signs of the disease after clinical therapy; and group 2, dogs that displayed worsening of the neurological signs or clinical stability. The data were all presented in tables and were submitted to paired t test and to logistic regression models to evaluate the influence of the RI reduction on both groups. There was no significant influence of the variables in the B-mode. After the treatment, the mean resistive index (RI was significantly lower for the group that presented clinical improvement. There was no significant difference of the mean RI reduction for the same artery when the right and left sides were compared. It could be concluded that transcranial duplex Doppler ultrasound is a method of cerebral hemodynamic assessment able to monitor more precisely the treatment of hydrocephalus in dogs and verify the responses.Foi realizada a ultrassonografia duplex Doppler transcraniana em 32 cães, conscientes, que apresentavam ventriculomegalia previamente detectada ao exame modo-B, para obter as medidas dos ventrículos laterais e os parâmetros de resistência das artérias cerebrais antes e depois de 30 dias de tratamento clínico. Os animais foram distribuídos em dois grupos: 1 - formado por cães que apresentaram remissão ou diminuição dos sinais clínicos após tratamento; 2 - por cães que apresentaram piora dos sinais neurológicos ou estabilidade do quadro clínico. Todos os dados foram dispostos em tabelas e submetidos ao teste t pareado e a modelos de regressão logística para avaliar a influência da redução do índice de resistividade (IR. Não foi

  5. Role of Duplex Doppler US for Thyroid Nodules: Looking for the 'Sword' Sign

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    Lacout, Alexis [Centre d' imagerie Me' dicale, Centre Me' dico Chirurgical, Aurillac (France); Marcy, Pierre Yves; Thariat, Juliette [Antoine Lacassagne Cancer Research Institute, Nice (France)

    2011-06-15

    Duplex Doppler US may be useful for the detection of thyroid malignancies that show either anarchic winding or penetrating 'sword like' neoangiogenic vessels. It may be helpful in selecting nodules that should undergo fine needle aspiration biopsy.

  6. Duplex-Doppler spectral analysis in the physiopathology of the temporomandibular joint.

    Science.gov (United States)

    Marini, M; Odoardi, G L; Bolle, G; Tartaglia, P

    1994-01-01

    We introduce a new method of analysis of the normal and abnormal behavior of the TMJ, using a duplex-doppler spectral analysis. The method consists in monitoring the joint movement by means of a study of the Fourier transformed signals, which give information on the velocity distribution of the condylo-meniscal complex during the opening and closing phases of the jaw. Using repeated sampling over short time intervals we get a detailed description of the motion which allows to discriminate the normal and abnormal action of the condylomeniscal complex. We are able to identify various physiopathological conditions, among which opening and/or closing clicks, complex locking conditions and anomalies related to an asymmetrical behavior during the operation cycle. Duplex-doppler spectral analysis is correlated to a clinical examination in order to define various classes of anomalies.

  7. Diagnosis of neonatal hemochromatosis with MR imaging and duplex Doppler sonography

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    Oddone, M.; Toma, P. [Dept. of Radiology, G. Gaslini Children' s Research Hospital, Genoa (Italy); Bellini, C.; Bonacci, W.; Bartocci, M.; Serra, G. [Department of Pediatrics, Neonatal Intensive Care Unit, University of Genoa, G. Gaslini Children' s Research Hospital, Largo G. Gaslini, 5, I-16147 Genoa (Italy)

    1999-07-01

    Neonatal hemochromatosis is a rare congenital disorder which affects both fetuses and newborns. It is characterized by hepatocellular failure, often appearing on the first day of life in the form of coagulopathy, hypoalbuminemia, hypoglycemia, and jaundice. Most of the affected infants die early in life, and definitive diagnosis has often been made only by post-mortem evaluation. With the help of MRI, plus increasing awareness of the disorder, diagnosis is now often made early, even in utero. Duplex Doppler sonography does not provide information on siderosis but shows abnormalities in the liver or blood-flow patterns associated with liver disease. (orig.)

  8. Renal duplex doppler ultrasonography in patients with recurrent urinary tract infection

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    Soliman Neveen

    2009-01-01

    Full Text Available Renal hemodynamics were studied using duplex Doppler ultrasonography in forty (33 females and 7 males; mean age: 12.1 ± 5.3 years normotensive patients with recurrent urinary tract infection and with no evidence of obstructive uropathy and age matched control group of 24 healthy children and adolescents. Resistivity index (RI and pulsatility index (PI in both arcuate (AA and interlobar (IA arteries were significantly higher in patients as compared to controls (P= 0.001, 0.01 respectively. Diastolic/systolic ratio (D/S at the same levels of renal vasculature (AA and IA was significantly lower in study patients as compared to their controls (P= 0.01, 0.001 respectively. Moreover, scarred renal units had higher RI and PI values as well as lower D/S ratio as compared to non scarred units (p= 0.01, 0.001, 0.001 respectively.. In conclusion, intra renal vascular resistivity is significantly increased in recurrent UTI patients particularly in those sus-taining renal scarring. Further follow up studies are recommended to determine if duplex assess-ment of intrarenal vasculature could be useful as an ancillary diagnostic and/or prognostic technique in the evaluation and follow up of recurrent UTI.

  9. Evaluation of Hepatic Vasculature in Fatty Liver Patients with Duplex Doppler Sonography

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    Nahid Sedighi

    2010-05-01

    Full Text Available Background/Objective: Duplex Doppler ultrasonography (US has been newly suggested as an important diagnostic technique in the non-invasive evaluation of hepatic vasculature and some hepatic parenchymal diseases. New findings suggest that diffuse fatty infiltration of the liver can alter normal hepatic vein and artery Doppler indices. The following study has been performed to evaluate the effect of fatty infiltration on portal vein indices."nPatients and Methods: Forty-eight patients with various degrees of fatty infiltration of the liver and 48 normal subjects without any signs of hepatic fatty infiltration in ultrasonography were examined using standard color Doppler sonography. Maximum and minimum peak velocity and resistance index were compared in the two groups."nResults: The mean of maximum peak velocity in the portal vein was 25.9±9.9 and 34.3±18.3 in the case and control group, respectively (P=0.006. The mean of minimum peak velocity in the portal vein was 19.2±9.9 and 18.7±8.7 in the case and control group, respectively (P=0.795. The mean of resistance index was 0.25±0.09 and 0.41±0.15 in the case and control group, respectively (P<0.001."nConclusion: The mean of maximum peak velocity and the mean of resistance index in the portal vein was significantly lower in patients with fatty infiltration compared to those who had no abnormality in the liver ultrasonography .

  10. Mobile Tele-echography: User Interface Design

    OpenAIRE

    Canero, Cristina; Thomos, Nikolaos; George A. Triantafyllidis; Litos, George; Strintzis, Michael G.

    2005-01-01

    Ultrasound imaging allows the evaluation of the degree of emergency of a patient. However, in several occasions a well trained sonographer is unavailable to perform such echography. To cope with this issue, the OTELO project aims to develop a fully integrated end-to-end mobile tele-echography system using an ultra light, remote-controlled robot, for population groups that are not served locally by medical experts. This paper focuses on the user interface of the OTELO system, consisted of the...

  11. Penile vascular diagnostic categorization using penile duplex Doppler ultrasound: Differences in vascular hemodynamics parameters by differences in anatomic sampling location

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    Fabio Pezzoni

    2016-10-01

    Full Text Available Objectives. In 2013 the International Society for Sexual Medicine(ISSM published the guidelines regarding the standard operating procedure (SOP for penile duplex Doppler ultrasound (PDDU. Although ISSM-SOP have given important strides in reducing interobserver variability in PDDU by procedural protocol and parameters these guidelines do not address the anatomic location along the penis at which hemodynamic measurements have to be done. In our opinion a “double sampling” may be interesting to detect the arteriogenic or venogenic nature of the erectile dysfunction (ED. In particular sampling measurements at the “crus” (at the level of the peno-scrotal junction may be significative for detection of veno-occlusive dysfunction (VOD,whereas an evaluation at “mid penis” (1/2 distance between peno-scrotal junction and coronal sulcus, may be useful to diagnose an arterial insufficiency (AI. Material and Methods. We evalued 90 men, mean age 56.3, affected with ED of medium degree, responder to PDE5-I that urdergone to PDDU and also responder after pharmacologic intracavernosal injection (PIIof prostaglandin E1 20 mcg, with rigid erection and normal maintenance. We moreover evalued 90 men in youthful age (mean 35.2, in absence of vascular risk factors, no responder to PDE5-I that undergone to PDDU by PII at high dosage (bimix: prostaglandin E1 20 mcg, papaverine 20 mg. Results. In the first pool the sampling at “mid penis” resulted significative for arterial insuffciency (AI in 81% (73, in presence of normal or borderline end diastolic velocity (EDV. Sampling at the “crus” resulted negative for VOD in 90% (81. In the second pool, 66.6% (60 resulted responder with rigid erection and normal maintenance in presence of normal hemodynamic parameters: peak systolic velocity (PSV and end diastolic velocity (EDV both at the “crus” and at “mid penis” sampling. 33.4% (30 responded with a semirigid erection and manifested a constant

  12. [Quality management in cardiovascular echography].

    Science.gov (United States)

    Gullace, Giuseppe

    2002-12-01

    The quality management of an organization can be defined as the ability to identify, plan and implement programs of measure, analysis, verification and control that allow to monitor management, resources, activities, processes and output/outcome of the same organization, including the satisfaction of the customers. Whatever the model used, it is demonstrated that the management-quality system, either for professional quality or for organization, turns out to be effective even in the health organizations within and to any level of organizational-structural complexity. The present paper concerns the experience of the Italian Society of Cardiovascular Echography (SIEC) on quality certification, both as a scientific society compared to other health organizations and to cardiovascular echo laboratories, and the definition of minimum requirements for the accreditation of the same laboratories. The model most frequently used for quality management is represented by the ISO 9000: Vision 2000, that is a management model with specific reference to the organization and the customer satisfaction. The model applied to the health structure needs a rapid change in mentality that addresses the operators to define, share and achieve objectives to be brought on by means of an active collaboration, group activity and deep sense of belonging necessary to the attainment of expected objectives. When the model is applied by a scientific society, it is necessary to take into account the different structural and functional organization, the constitution and the operators differing on the point of view of origin, experiences, mentality, and roles. The ISO 9000: Vision 2000 model can be applied also to the cardiovascular echo laboratory which may be compared to a simple organization; for its corrected functioning, SIEC has defined minimal requirements for the accreditation, realization and modalities to carry out and manage quality. The quality system represents a new way of operating of an

  13. Mobile tele-echography: user interface design.

    Science.gov (United States)

    Cañero, Cristina; Thomos, Nikolaos; Triantafyllidis, George A; Litos, George C; Strintzis, Michael Gerassimos

    2005-03-01

    Ultrasound imaging allows the evaluation of the degree of emergency of a patient. However, in some instances, a well-trained sonographer is unavailable to perform such echography. To cope with this issue, the Mobile Tele-Echography Using an Ultralight Robot (OTELO) project aims to develop a fully integrated end-to-end mobile tele-echography system using an ultralight remote-controlled robot for population groups that are not served locally by medical experts. This paper focuses on the user interface of the OTELO system, consisting of the following parts: an ultrasound video transmission system providing real-time images of the scanned area, an audio/video conference to communicate with the paramedical assistant and with the patient, and a virtual-reality environment, providing visual and haptic feedback to the expert, while capturing the expert's hand movements. These movements are reproduced by the robot at the patient site while holding the ultrasound probe against the patient skin. In addition, the user interface includes an image processing facility for enhancing the received images and the possibility to include them into a database.

  14. Tele-Operated Echography and Remote Guidance for Performing Tele-Echography on Geographically Isolated Patients

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    Philippe Arbeille

    2016-06-01

    Full Text Available Objective: To evaluate the performance of three tele-echography systems for routine use in isolated medical centers. Methods: Three systems were used for deep (abdomen, pelvis, fetal and superficial (muscle, thyroid, carotid artery examinations: (a a robotic arm (RA holding an echographic probe; (b an echograph with a motorized probe (MP; and (c remote guidance (RG where the patient site operator performed the examination assisted by an expert via videoconference. All systems were tested in the same medical center located 60 km away from the university hospital. Results: A total of 340 remote echography examinations were performed (41% RA and MP, 59% RG. MP and RA allowed full control of the probe orientation by the expert, and provided diagnoses in 97% of cases. The use of RG was sufficient for superficial vessel examinations and provided diagnoses in 98% of cases but was not suited for deep or superficial organs. Assessment of superficial organs was best accomplished using the MP. Discussion: Both teleoperated systems provided control of the probe orientation by the expert necessary for obtaining appropriate views of deep organs but the MP was much more ergonomic and easier to use than the RA. RG was appropriate for superficial vessels while the MP was better for superficial volumic organs.

  15. Tele-Operated Echography and Remote Guidance for Performing Tele-Echography on Geographically Isolated Patients

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    Arbeille, Philippe; Zuj, Kathryn; Saccomandi, Arnaud; Andre, Elise; De La Porte, Cedric; Georgescu, Monica

    2016-01-01

    Objective: To evaluate the performance of three tele-echography systems for routine use in isolated medical centers. Methods: Three systems were used for deep (abdomen, pelvis, fetal) and superficial (muscle, thyroid, carotid artery) examinations: (a) a robotic arm (RA) holding an echographic probe; (b) an echograph with a motorized probe (MP); and (c) remote guidance (RG) where the patient site operator performed the examination assisted by an expert via videoconference. All systems were tested in the same medical center located 60 km away from the university hospital. Results: A total of 340 remote echography examinations were performed (41% RA and MP, 59% RG). MP and RA allowed full control of the probe orientation by the expert, and provided diagnoses in 97% of cases. The use of RG was sufficient for superficial vessel examinations and provided diagnoses in 98% of cases but was not suited for deep or superficial organs. Assessment of superficial organs was best accomplished using the MP. Discussion: Both teleoperated systems provided control of the probe orientation by the expert necessary for obtaining appropriate views of deep organs but the MP was much more ergonomic and easier to use than the RA. RG was appropriate for superficial vessels while the MP was better for superficial volumic organs. PMID:27304972

  16. A user interface for mobile robotized tele-echography

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    Triantafyllidis, G.A. [Informatics and Telematics Institute ITI-CERTH, Thessaloniki (Greece)]. E-mail: gatrian@iti.gr; Thomos, N. [Informatics and Telematics Institute ITI-CERTH, Thessaloniki (Greece); Canero, C. [Computer Vision Center, UAB, Barcelona (Spain); Vieyres, P. [Laboratoire Vision and Robotique Universite d' Orleans, Bourges (France); Strintzis, M.G. [Informatics and Telematics Institute ITI-CERTH, Thessaloniki (Greece)

    2006-12-20

    Ultrasound imaging allows the evaluation of the degree of emergency of a patient. However, in many situations no experienced sonographer is available to perform such echography. To cope with this issue, the OTELO project 'mObile Tele-Echography using an ultra-Light rObot' (OTELO) aims to develop a fully integrated end-to-end mobile tele-echography system using an ultralight, remotely controlled six degree-of-freedom (DOF) robot. In this context, this paper deals with the user interface environment of the OTELO system, composed by the following parts: an ultrasound video transmission system providing real-time images of the scanned area at each moment, an audio/video conference to communicate with the paramedical assistant and the patient, and finally a virtual reality environment, providing visual and haptic feedback to the expert, while capturing the expert's hand movements with a one-DOF hand free input device.

  17. AGU-WP-1 Echographie de contraste et kystes renaux

    National Research Council Canada - National Science Library

    Cazals, X; Bleuzen, A; Favelle, O; Bruyère, F; Patat, F; Brunereau, L

    2009-01-01

    ... dans les lesions kystiques de type 2F et 3 de la classification Bosniak. Mots cles : Rein, kyste - Echographie AGU-WS-2 APPORT DE LA TOMODENSITOMETRIE DANS LES TRAUMATISMES DU REIN : A PROPOS DE 22 CAS H Zian, I Nassar, S Belkacem, L Hammani, S Bouklata A Ajana F Imani Rabat - Maroc Objectifs : Demontrer la place de la TDM dans le bilan des lesions r...

  18. Role of echography in diagnostic dilemma in choroidal masses

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    Kopal N Mithal

    2014-01-01

    Full Text Available Purpose: To evaluate the role of echography in diagnosis and management of a diverse array of choroidal masses. Materials and Methods: Sixty-two cases of clinically suspected choroidal masses were prospectively analyzed with B-scan (10 Hz, A-scan, and ultrasound biomicroscopy (UBM (50 Hz after a meticulous history and ocular examination. Ancillary investigations and systemic evaluation were also done. Results: Based on clinical suspicion, acoustic features, response to treatment, and other ancillary tests combined together, the various masses were differentiated. The cases included in the study were as follows: n = 10 malignant melanomas, n = 16 metastasis and infiltrations, n = 9 hemangioma, n = 7 tuberculoma, n = 8 nonspecific inflammatory masses, n = 2 disciform plaques, n = 4 macular cysts or retinoschisis, n = 2 Coat′s disease, n = 1 melanocytoma, and n = 2 osteomas. Ultrasonography (USG alone could identify n = 51 lesions, while UBM in combination with USG was needed in remaining 11 masses. Conclusion: Standardized echography is an important adjunct in the diagnosis and management of eyes with intraocular masses. A better understanding of the clinicopathological and echographic picture of the diverse lesions can help in detection, differentiation, diagnosis, proposing a therapeutic approach, and also monitoring response to treatment. Echography is essential to evaluate tumors for extrascleral and anterior segment extension.

  19. Primary chronic venous insufficiency of the lower extremities: preoperative color duplex Doppler ultrasound study; Insuficiencia venosa cronica primaria de los miembros inferiores. Valoracion prequirurgica con ecografia Doppler duplex color

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    Selfa, S.; Diago, T.; Ricart, M.; Chulia, R.; Martin, F. [Hospital Lluis Xativa. Valencia (Spain)

    2000-07-01

    To asses the role of color duplex Doppler ultrasound (CDU) in the preoperative study of patients with varicose veins in lower extremities. We employed CDU to examine varicose veins in 342 lower limbs, assessing reflux in saphenous veins (SV), deep venous system (DVS) and perforating veins (PV). We analyzed the relationship between the anatomical extent of the reflux and the clinical findings. Insufficiency of the superficial venous system alone was uncommon, occurring in only 10.8% of the limbs examined. Reflux was observed in SV and PV in 48.2% of the legs. It was detected in all three systems in 29.2% of cases. The presence of reflux in more than one system and more than one value was associated with increased clinical severity. The site of venous reflux in lower extremities with varicose veins varies. Greater clinical severity is observed in the presence of more marked reflux in the DVS and PV. CDU provides anatomic and functional data on the three venous systems of the lower limbs, allowing an individualized therapeutic surgery. Preoperative localization of incompetent PV by means of CDU facilities their ligation. CDU is the technique of choice for the preoperative examination of the venous systems of patients with varicose veins. (Author)

  20. Adequacy and quality of abdominal echographies requested by primary care professionals

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    Auladell Ma

    2010-09-01

    Full Text Available Abstract Background The value of abdominal echography in primary care is great because it is innocuous, inexpensive, easy to perform and provides a great deal of information making this the first examination to be requested in cases of probable abdominal disease. However, too many abdominal echographies are probably requested overcrowding the Departments of Radiodiagnosis with not always justified petitions or with repetition of tests based on little clinical criteria. Methods/Design The aim of the study is to evaluate the adequacy and quality of abdominal echographies requested by primary care physicians in the Maresme County (North of Barcelona, develop guidelines for indicating echographies and reevaluate this adequacy after implementing these guidelines. We will perform a two-phase study: the first descriptive, and retrospective evaluating the adequacy and quality of petitions for abdominal echographies, and in the second phase we will evaluate the impact of recommendations for indicating abdominal echographies for PC physicians on the adequacy and quality of echography petitions thereafter. This study will be carried out in 10 primary care centres in the Maresme (Barcelona. 1067 abdominal echographies requested by primary care physicians from the above mentioned centres from January 2007 to April 2010 and referred to the Department of Radiology and the same number of applications after the intervention. All the petitions for abdominal echographies requested will be analysed and the clinical histories will be obtained to determine demographic variables, the reason for the visit and for the echography petition and diagnostic orientation, clinical and echographic data, evaluation of the echographies according to the quality and variables characterising the professionals requesting the echographies including: age, sex, laboral situation, length of time in work post, formation, etc. To achieve a consensus of the adequacy of abdominal echography

  1. Activity of Crohn's disease assessed by colour Doppler ultrasound analysis of the affected loops.

    Science.gov (United States)

    Esteban, J M; Maldonado, L; Sanchiz, V; Minguez, M; Benages, A

    2001-01-01

    The aim of this study was to evaluate with colour Doppler ultrasound the vascular changes in the wall of the loops affected by Crohn's disease, and to establish whether these changes reflects clinical or biochemical activity of Crohn's disease. Seventy-nine patients with Crohn's disease (44 with active disease and 35 inactive patients) were studied with frequency- and amplitude-encoded duplex Doppler sonography. A group of 35 healthy volunteers were also included. The exam consisted of the search for colour signals in the walls of the loops affected by Crohn's disease, classifying the degree of vascularity with a simple scoring system into three groups: absence of colour signal (score of 0); weak or scattered colour signals (score of 1); and multiple colour signals or clear identification of vessels in the loops walls (score of 2). Doppler curves were obtained of the detected vessels with measurement of the resistive index (RI). There was a visible increase in the gut walls' vascularity in the active patients compared with those with inactive disease. The mean RI was statistically significantly lower in the gut wall vessels of the patients with active illness than that obtained in the inactive patients. Colour Doppler ultrasound is a useful tool in the assessment of activity in Crohn's disease.

  2. Adequacy and quality of abdominal echographies requested by primary care professionals

    OpenAIRE

    Auladell Ma; Caballeria Llorenç; Pera Guillem; Rodríguez Lluís; Casas José; Aznar Jesús; Miranda Dolores; Sánchez Carmen; Negrete Antonio; Castellví Josep; Bernad Jesús; Canut Santiago; Aubà Josep; Aizpurua Miren; Torán Pere

    2010-01-01

    Abstract Background The value of abdominal echography in primary care is great because it is innocuous, inexpensive, easy to perform and provides a great deal of information making this the first examination to be requested in cases of probable abdominal disease. However, too many abdominal echographies are probably requested overcrowding the Departments of Radiodiagnosis with not always justified petitions or with repetition of tests based on little clinical criteria. Methods/Design The aim ...

  3. Colour Studies

    African Journals Online (AJOL)

    DR Nneka

    2015-04-14

    Apr 14, 2015 ... behaviour of colour and develop colour originality through creative construction and ... augmented by advertising that links color to desire for everything ...... Illusion's Bias on Serving and Eating Behaviour Journal of consumer.

  4. [Ultrasound diagnostics in ophthalmology (standardized echography): part 2: diseases of the orbit - ultrasound biomicroscopy diagnostics].

    Science.gov (United States)

    Hasenfratz, G; Mardin, C

    2014-11-01

    Ultrasound diagnostics have been one of the most important noninvasive supplementary diagnostic procedures in ophthalmology for many decades and are indispensable for many intraocular and orbital diseases. When the echography examination and analysis of the echograms obtained are correctly carried out, ultrasound diagnostics are characterized by a high measure of specificity and sensitivity.

  5. Measuring Colour

    CERN Document Server

    Hunt, R W G

    2011-01-01

    The classic authority on colour measurement now fully revised and updated with the latest CIE recommendations The measurement of colour is of major importance in many commercial applications, such as the textile, paint, and foodstuff industries; as well as having a significant role in the lighting, paper, printing, cosmetic, plastics, glass, chemical, photographic, television, transport, and communication industries. Building upon the success of earlier editions, the 4th edition of Measuring Colour has been updated throughout with new chapters on colour rendering by light sources; colorimetry

  6. The Clinical Signiifcance of Colour Duplex Ultrasonography in the the Diagnosis of Chronic Venous Insufifciency of Lower Limbs%双功多普勒彩超诊断慢性下肢静脉功能不全的临床意义分析

    Institute of Scientific and Technical Information of China (English)

    张微

    2015-01-01

    Objective To analyse the clinical significance of colour duplex ultrasonography in patients with chronic venous insufficiency in lower limbs. Methods 94 patients in our hospital with chronic venous insufficiency were taken as research subjects, used venous antegrade implementation angiography and duplex doppler ultrasonography. Compared the test results of two methods, and analysed advantage by using duplex doppler ultrasound diagnosis of lower extremity venous insufifciency. Results Duplex doppler ultrasonography of lower extremity venous trafifc detection rate was signiifcantly higher than venous antegrade contrast, the misdiagnosis rate was signiifcantly lower than veins antegrade venous angiography. Conclusion The duplex doppler ultrasound in the diagnosis of deep venous insufficiency is convenient, safe and can effectively improve the accuracy of clinical diagnosis.%目的:探讨双功多普勒彩超在慢性下肢静脉功能不全患者临床诊断中的应用价值。方法选取我院收治的94例慢性下肢静脉功能不全患者作为研究对象,对该组患者实施下肢静脉顺行造影和双功多普勒彩超检查。对比两种检测方法的检测结果,分析采用双功多普勒彩超诊断下肢静脉功能不全的优势。结果双功多普勒彩超检查下肢交通静脉的检出率高于下肢静脉顺行造影,对交通静脉的漏诊率低于下肢静脉顺行造影。结论应用双功多普勒彩超诊断下肢深静脉功能不全患者进行,便捷、安全,可有效提高临床诊断准确率。

  7. Colour schemes

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2013-01-01

    This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

  8. Advances in robotic tele-echography services--the OTELO system.

    Science.gov (United States)

    Courreges, F; Vieyres, P; Istepanian, R S H

    2004-01-01

    This paper presents some of the recent advances in mobile robotic tele-echography systems. It discussed the feasibility of a reliable remote ultrasound examination using such robotic systems in wireless environments. That is to say, to make use emerging wireless communications to provide a medical expert or consultant the ability to examine a remote patient. A critical issue of such systems is the accurate interactivity between both remote sides. The paper presents a robotic teleoperated OTELO (mobile tele-echography using an ultra-light robot) system for such purposes. The paper presents an overview of the system and some of preliminary tests and the use of wireless communication in this e-health application.

  9. ECHOGRAPHY POTENTIAL IN DIAGNOSTICS OF THE KNEE JOINT IMPAIRMENT IN THE EVENT OF THE JUVENILE ARTHRITIDES

    Directory of Open Access Journals (Sweden)

    N.V. Osipova

    2008-01-01

    Full Text Available The juvenile rheumatoid arthritis (JRA is one of the most widely spread rheumatic diseases among children, which is characterized by the steady progressive run, rapidly leading to the disability. Among numerous JRA manifestations, one of the leading is the joint syndrome with children mostly suffering from the knee joint impairment. With JRA, the initial changes in the joints affect the joint tissues and articular cartilage, while the bone changes evolve at the late stages of the disease. As a result, the echography plays an important role in the early arthritides diagnostics if compared to the x ray study and computerized tomography. To identify the typical features of the knee joint impairment, 97 children with JRA and 16 children with the juvenile spondyl arthritis (JSA underwent the high pitched linear transducer assisted echography. The overwhelming majority of patients showed the changes in the hyaline cartilage. The hyperechoic enlargements in the depth of the cartilage were typical of JRA, while the cartilage thinning was typical of JSA. About a half of the patients showed the effusion. Over a third of the patients showed the changes in the cortical layer of the articular bone surface.Key words: juvenile rheumatoid arthritis, juvenile spondyl arthritis, diagnostics, knee joint echography, children.

  10. Covert colour processing in colour agnosia.

    Science.gov (United States)

    Nijboer, Tanja C W; van Zandvoort, Martine J E; de Haan, Edward H F

    2006-01-01

    Patients with colour agnosia can perceive colours and are able to match coloured patches on hue, but are unable to identify or categorise colours. It is a rare condition and there is as yet no agreement on the clinical definition or a generally accepted explanation. In line with observations from object agnosia and prosopagnosia, we hypothesised that (some of) these patients might still be able to process colour information at an implicit level. In this study, we investigated this possibility of implicit access to colour semantics and colour names in a man (MAH) who suffers from developmental colour agnosia. We designed two experimental computer tasks: an associative colour priming task with a lexical decision response and a reversed Stroop task. The results of these experiments suggest that there is indeed automatic processing of colour, although MAH was unable to explicitly use colour information.

  11. Customized CT angiogram planning for intraoperative transesophageal echography-guided endovascular exclusion of thoracic aorta penetrating ulcer.

    Science.gov (United States)

    Piazza, Michele; Lupia, Mario; Grego, Franco; Antonello, Michele

    2015-04-01

    The technique is demonstrated in a 78-year-old man; the preoperative CT angiogram showed a descending thoracic aorta ulcer of 5.9 cm in maximum diameter and 3.8 cm longitudinal extension. A ZTEG-2P-36-127-PF (Cook Medical) single tubular endograft was planned to be deployed. From the preoperative CT angiogram we planned to land 4.7 cm above the midline of the descending thoracic aorta ulcer and 8.0 cm below. In the operating room, under radioscopic vision the centre of the transesophageal echography probe was used as marker to identify the correspondent midline of the descending thoracic aorta ulcer and a centimeter-sized pigtail catheter in the aorta was used to calculate the desired length above and below the ulcer midline. The endograft was introduced and placed in the desired position compared to the transesophageal echography probe and the catheter; under transesophageal echography vision the graft was finally deployed. The CT angiogram at 1 month showed the correct endograft position, descending thoracic aorta ulcer exclusion with no signs of endoleak. In selected cases, this method allows planning in advance safe stent graft positioning and deployment totally assisted by transesophageal echography, with no risk of periprocedural contrast-related renal failure and reduced radiation exposure for the patient and operators.

  12. Realtime or Delayed Tele-Echography Using (A) a Robotic Arm, ISDN or Satellite Lines, (B) a Volumic Echographic Capture Mode and Internet (Application to Abdomen and Fetus)

    Science.gov (United States)

    Arbeille, Ph.; Cloppet, F.; Boucher, A.; Capri, A.; Vincent, N.

    2008-06-01

    Objective: to test (a) the tele-echography in realtime based on the use of a robotic arm, (b) the delayed tele echography using a volumic echographic capture and delayed processing. Method: A dedicated robotic arm (ESTELE) holding a real ultrasound probe is remotely controlled from the expert site with a fictive probe, and reproduces on the real probe all the movements of the expert hand. A dedicated motorized probe holder (TILTER) was used for tilting a 2D probe from -45 to +45°. Results: During fetal robotized Tele-echography (n=50) the expert was able to visualize and measure the fetal structures in 95% of the cases, while during abdomen echography (n=87) the expert visualized the main organs and lesions in 87% of the cases. The mean duration of the robotized tele echography session for one patient was 20+/-10 min. The delayed echography using the TILTER was tested on 40 patients. The organs were adequately visualized in 85% of the cases after 3 capture per organ. The average time from the first capture until the diagnostic was delivered was 40+/-10 minutes. Conclusion: Realtime or delayed Tele-echography provide similar information as direct examination in at least 85% of the cases. No false diagnostic was reported.

  13. Plasmonic colour generation

    DEFF Research Database (Denmark)

    Kristensen, Anders; Yang, Joel K. W.; Bozhevolnyi, Sergey I.

    2016-01-01

    Plasmonic colours are structural colours that emerge from resonant interactions between light and metallic nanostructures. The engineering of plasmonic colours is a promising, rapidly emerging research field that could have a large technological impact. We highlight basic properties of plasmonic...

  14. Colour Guided Colour Image Steganography

    CERN Document Server

    Amirtharajan, R; Swarup, Motamarri Abhilash; K, Mohamed Ashfaaq; Rayappan, John Bosco Balaguru

    2010-01-01

    Information security has become a cause of concern because of the electronic eavesdropping. Capacity, robustness and invisibility are important parameters in information hiding and are quite difficult to achieve in a single algorithm. This paper proposes a novel steganography technique for digital color image which achieves the purported targets. The professed methodology employs a complete random scheme for pixel selection and embedding of data. Of the three colour channels (Red, Green, Blue) in a given colour image, the least two significant bits of any one of the channels of the color image is used to channelize the embedding capacity of the remaining two channels. We have devised three approaches to achieve various levels of our desired targets. In the first approach, Red is the default guide but it results in localization of MSE in the remaining two channels, which makes it slightly vulnerable. In the second approach, user gets the liberty to select the guiding channel (Red, Green or Blue) to guide the r...

  15. Robot-based tele-echography: clinical evaluation of the TER system in abdominal aortic exploration

    CERN Document Server

    Martinelli, Thomas; Bressollette, Luc; Pelissier, Franck; Boidard, Eric; Troccaz, Jocelyne; Cinquin, Philippe

    2007-01-01

    OBJECTIVE: The TER system is a robot-based tele-echography system allowing remote ultrasound examination. The specialist moves a mock-up of the ultrasound probe at the master site, and the robot reproduces the movements of the real probe, which sends back ultrasound images and force feedback. This tool could be used to perform ultrasound examinations in small health care centers or from isolated sites. The objective of this study was to prove, under real conditions, the feasibility and reliability of the TER system in detecting abdominal aortic and iliac aneurysms. METHODS: Fifty-eight patients were included in 2 centers in Brest and Grenoble, France. The remote examination was compared with the reference standard, the bedside examination, for aorta and iliac artery diameter measurement, detection and description of aneurysms, detection of atheromatosis, the duration of the examination, and acceptability. RESULTS: All aneurysms (8) were detected by both techniques as intramural thrombosis and extension to the...

  16. Developmental colour agnosia.

    Science.gov (United States)

    van Zandvoort, Martine J E; Nijboer, Tanja C W; de Haan, Edward

    2007-08-01

    Colour agnosia concerns the inability to recognise colours despite intact colour perception, semantic memory for colour information, and colour naming. Patients with selective colour agnosia have been described and the deficit is associated with left hemisphere damage. Here we report a case study of a 43-year-old man who was referred to us with a stroke in his right cerebellar hemisphere. During the standard assessment it transpired that he was unable to name coloured patches. Detailed assessment of his colour processing showed that he suffers from a selective colour agnosia. As he claimed to have had this problem all his life, and the fact that the infratentorial infarct that he had incurred was in an area far away from the brain structures that are known to be involved in colour processing, we suggest that he is the first reported case of developmental colour agnosia.

  17. Interactions between colour and synaesthetic colour: an effect of simultaneous colour contrast on synaesthetic colours.

    Science.gov (United States)

    Nijboer, Tanja C W; Gebuis, Titia; te Pas, Susan F; van der Smagt, Maarten J

    2011-01-01

    We investigated whether simultaneous colour contrast affects the synaesthetic colour experience and normal colour percept in a similar manner. We simultaneously presented a target stimulus (i.e. grapheme) and a reference stimulus (i.e. hash). Either the grapheme or the hash was presented on a saturated background of the same or opposite colour category as the synaesthetic colour and the other stimulus on a grey background. In both conditions, grapheme-colour synaesthetes were asked to colour the hash in a colour similar to the synaesthetic colour of the grapheme. Controls that were pair-matched to the synaesthetes performed the same experiment, but for them, the grapheme was presented in the colour induced by the grapheme in synaesthetes. When graphemes were presented on a grey and the hash on a coloured background, a traditional simultaneous colour-contrast effect was found for controls as well as synaesthetes. When graphemes were presented on colour and the hash on grey, the controls again showed a traditional simultaneous colour-contrast effect, whereas the synaesthetes showed the opposite effect. Our results show that synaesthetic colour experiences differ from normal colour perception; both are susceptible to different surrounding colours, but not in a comparable manner.

  18. Synaesthesia and colour constancy.

    Science.gov (United States)

    Erskine, Holly; Mattingley, Jason B; Arnold, Derek H

    2013-04-01

    Grapheme-colour synaesthesia is an atypical condition characterized by the perception of colours when reading achromatic text. We investigated the level of colour processing responsible for these experiences. To do so, we tapped a central characteristic of colour perception. In different lighting conditions the same wavelength of light can prompt the perception of different colours. This helps humans recognize distinctive coloured objects despite changes in illumination. We wanted to see if synaesthetic colours were generated at a neural locus that was susceptible to colour constancy analyses. We used colour matching and naming tasks to examine interactions between simulated coloured illuminants and synaesthetic colours. Neither synaesthetic colour matching or naming was impacted. This contrasted with non-synaesthetic control participants, who performed the colour-matching task with graphemes physically coloured to mimic synaesthesia. Our data suggest that synaesthetic colour signals are not generated at lower-levels of colour processing, but are introduced at higher levels of analysis and are therefore not impacted by the processes responsible for perceptual constancy.

  19. Can colour be measured?

    DEFF Research Database (Denmark)

    Ramanujam, P.S.

    Colour is a sensation. While wavelength can be measured with a spectrometer consisting of dispersive elements and colour insensitive detectors, detection of colour is accomplished by the eye, equipped with a lens, colour sensitive detectors, and a powerful processor in the form of brain. Sometimes...

  20. Duplex Doppler ultrasound study of the temporomandibular joint.

    Science.gov (United States)

    Stagnitti, A; Marini, A; Impara, L; Drudi, F M; Lo Mele, L; Lillo Odoardi, G

    2012-06-01

    Sommario INTRODUZIONE: La fisiologia articolare dell’articolazione temporo-mandibolare (ATM) può essere esaminata sia dal punto di vista clinico che strumentale. La diagnostica per immagini ha da tempo contribuito con la risonanza magnetica (RM) e anche con la radiografia (Rx) e la tomografia computerizzata (TC) all’analisi della morfologia dei capi articolari e della cinetica condilare. L’esame duplex-ecodoppler è una metodica di largo impiego nello studio delle strutture in movimento in particolar modo a livello delle strutture del sistema vascolare. MATERIALI E METODI: È stata utilizzata un’apparecchiatura Toshiba APLIO SSA-770A, con l’uso di tecnica duplex-ecodoppler multi display, che consente la visualizzazione contemporanea dell’immagine ecografica e dei segnali Doppler utilizzando una sonda lineare del tipo phased array con cristalli trasduttori funzionanti ad una frequenza fondamentale di 6 MHz per gli spettri Doppler pulsati e 7.5 MHz per l’imaging ecografico. Sono stati esaminati nel Dipartimento di Scienze Radiologiche, Oncologiche e Anatomo-patologiche dell’Università “Sapienza” di Roma, 30 pazienti del reparto di Ortognatodonzia dell’Istituto di Odontoiatria della stessa Università. RISULTATI: Nei pazienti normali si è ottenuta un’alternanza regolare degli spettri Doppler, mentre nei soggetti con disfunzioni del complesso condilo-meniscale, si è persa la regolarità della sommatoria degli spettri di Fourier, con altezze incostanti in relazione a spostamenti irregolari del complesso condilo-meniscale. CONCLUSIONI: L’esame ecodoppler si è dimostrato, in tutti i pazienti, capace di discriminare quelli normali dai patologici e tra questi ultimi ha permesso di identificare gli aspetti più significativi delle patologie disfunzionali.

  1. Development of 3D space-sharing interface using augmented reality technology for domestic tele-echography.

    Science.gov (United States)

    Yoshinaga, Takashi; Horiguchi, Tomohiro; Miyazaki, Wataru; Masuda, Kohji

    2009-01-01

    We propose a domestic tele-echography system linking between the patient's home and a hospital because of the demand due to increase in the number of patients by aging society and recent progress in portable echography enabled us to develop this system. In previous researches three-dimensional position of the ultrasound probe was difficult to specify because a remote doctor observe the patient through a video camera. Therefore we have developed a reproduction system of the probe position and angle using the ARToolKit and GUI interface using OpenGL. Only an USB camera and two markers for the body surface and the probe are necessary to memorize and transfer three-dimensional position of the probe. We have also designed a doctor side interface including echogram, patient scene and CG to instruct probe operation. As a result of evaluation experiments, guided position was satisfied to reproduce the echogram for diagnosis.

  2. Recolouring-resistant colourings

    DEFF Research Database (Denmark)

    Pedersen, A. S.; Rautenbach, D.

    2011-01-01

    We study colourings of graphs with the property that the number of used colours cannot be reduced by applying some recolouring operation. A well-studied example of such colourings are b-colourings, which were introduced by Irving and Manlove [R.W. Irving, D.F. Manlove, The la-chromatic number...... of a graph, Discrete Appl. Math. 91 (1999) 127-141]. Given a graph and a colouring, a recolouring operation specifies a set of vertices of the graph on which the colouring can be changed. We consider two such operations: One which allows the recolouring of all vertices within some given distance of some...

  3. Coloured Hopf algebras

    CERN Document Server

    Quesne, C

    1997-01-01

    Quite recently, a ``coloured'' extension of the Yang-Baxter equation has appeared in the literature and various solutions of it have been proposed. In the present contribution, we introduce a generalization of Hopf algebras, to be referred to as coloured Hopf algebras, wherein the comultiplication, counit, and antipode maps are labelled by some colour parameters. The latter may take values in any finite, countably infinite, or uncountably infinite set. A straightforward extension of the quasitriangularity property involves a coloured universal ${\\cal R}$-matrix, satisfying the coloured Yang-Baxter equation. We show how coloured Hopf algebras can be constructed from standard ones by using an algebra isomorphism group, called colour group. Finally, we present two examples of coloured quantum universal enveloping algebras.

  4. Practical colour management

    Science.gov (United States)

    Williams, Susan

    2006-06-01

    Spectrophotometers have been successfully used for colour measurement. This paper addresses digital imaging as a complementary and alternative method of colour measurement and appearance and an effective communication tool as part of a practical colour management programme within the supply chain of a textile retailer. The specific needs—to measure and communicate textured dyed material and printed fabric—are discussed, as well as the colour specification and quality control (QC) of currently un-measurable fabrics and accessories. A unique method of using digital imaging for the assessment of colour fastness will also be discussed.

  5. Is colour cognitive?

    Science.gov (United States)

    Skorupski, Peter; Chittka, Lars

    2011-03-01

    In recent years, colour-vision abilities have been rather generously ascribed to various invertebrates and even bacteria. This uncertainty of when to diagnose colour vision stems in part from confusing what colour vision can do with what it is. What colour vision can do is discriminate wavelength independent of intensity. However, if we take this as a definition of what colour vision is, then we might be obliged to conclude that some plants and bacteria have colour vision. Moreover, there is a similar confusion of what are necessary and what are sufficient mechanisms and behavioural abilities for colour vision. To humans, seeing in colour means seeing an image in which objects/lights have chromatic attributes—in contrast to the sensation that we have when viewing monochrome movies, or our experience in dim light when only rod vision is possible. The necessary basic equipment for this is to have at least two types of photoreceptors that differ in spectral sensitivity, and at least one type of spectrally opponent cell to compare the signals from the photoreceptors. Clearly, however, a necessary additional prerequisite for colour vision is to have vision, which entails the identification of shapes, sizes and locations of objects in the world. Thus, if an animal has colour vision, it should see an image in which distinct objects/lights have colour attributes. This distinguishes colour vision from wavelength discrimination, but also from what has historically been called wavelength-specific behaviour: a type of behaviour triggered by fixed configurations of spectral receptor signals; however, we discuss difficulties in diagnosing wavelength-specific behaviour as an indicator of the absence of colour vision. Finally, we discuss whether colour vision, by definition, contains a cognitive dimension for ordering and classifying perceptual experience.

  6. Colour constancy in insects.

    Science.gov (United States)

    Chittka, Lars; Faruq, Samia; Skorupski, Peter; Werner, Annette

    2014-06-01

    Colour constancy is the perceptual phenomenon that the colour of an object appears largely unchanged, even if the spectral composition of the illuminating light changes. Colour constancy has been found in all insect species so far tested. Especially the pollinating insects offer a remarkable opportunity to study the ecological significance of colour constancy since they spend much of their adult lives identifying and choosing between colour targets (flowers) under continuously changing ambient lighting conditions. In bees, whose colour vision is best studied among the insects, the compensation provided by colour constancy is only partial and its efficiency depends on the area of colour space. There is no evidence for complete 'discounting' of the illuminant in bees, and the spectral composition of the light can itself be used as adaptive information. In patchy illumination, bees adjust their spatial foraging to minimise transitions between variously illuminated zones. Modelling allows the quantification of the adaptive benefits of various colour constancy mechanisms in the economy of nature. We also discuss the neural mechanisms and cognitive operations that might underpin colour constancy in insects.

  7. A colour image reproduction framework for 3D colour printing

    Science.gov (United States)

    Xiao, Kaida; Sohiab, Ali; Sun, Pei-li; Yates, Julian M.; Li, Changjun; Wuerger, Sophie

    2016-10-01

    In this paper, the current technologies in full colour 3D printing technology were introduced. A framework of colour image reproduction process for 3D colour printing is proposed. A special focus was put on colour management for 3D printed objects. Two approaches, colorimetric colour reproduction and spectral based colour reproduction are proposed in order to faithfully reproduce colours in 3D objects. Two key studies, colour reproduction for soft tissue prostheses and colour uniformity correction across different orientations are described subsequently. Results are clear shown that applying proposed colour image reproduction framework, performance of colour reproduction can be significantly enhanced. With post colour corrections, a further improvement in colour process are achieved for 3D printed objects.

  8. Dynamic plasmonic colour display

    Science.gov (United States)

    Duan, Xiaoyang; Kamin, Simon; Liu, Na

    2017-02-01

    Plasmonic colour printing based on engineered metasurfaces has revolutionized colour display science due to its unprecedented subwavelength resolution and high-density optical data storage. However, advanced plasmonic displays with novel functionalities including dynamic multicolour printing, animations, and highly secure encryption have remained in their infancy. Here we demonstrate a dynamic plasmonic colour display technique that enables all the aforementioned functionalities using catalytic magnesium metasurfaces. Controlled hydrogenation and dehydrogenation of the constituent magnesium nanoparticles, which serve as dynamic pixels, allow for plasmonic colour printing, tuning, erasing and restoration of colour. Different dynamic pixels feature distinct colour transformation kinetics, enabling plasmonic animations. Through smart material processing, information encoded on selected pixels, which are indiscernible to both optical and scanning electron microscopies, can only be read out using hydrogen as a decoding key, suggesting a new generation of information encryption and anti-counterfeiting applications.

  9. Topographical coloured plasmonic coins

    CERN Document Server

    Guay, Jean-Michel; Côté, Guillaume; Charron, Martin; Ramunno, Lora; Berini, Pierre; Weck, Arnaud

    2016-01-01

    The use of metal nanostructures for colourization has attracted a great deal of interest with the recent developments in plasmonics. However, the current top-down colourization methods based on plasmonic concepts are tedious and time consuming, and thus unviable for large-scale industrial applications. Here we show a bottom-up approach where, upon picosecond laser exposure, a full colour palette independent of viewing angle can be created on noble metals. We show that colours are related to a single laser processing parameter, the total accumulated fluence, which makes this process suitable for high throughput industrial applications. Statistical image analyses of the laser irradiated surfaces reveal various distributions of nanoparticle sizes which control colour. Quantitative comparisons between experiments and large-scale finite-difference time-domain computations, demonstrate that colours are produced by selective absorption phenomena in heterogeneous nanoclusters. Plasmonic cluster resonances are thus fo...

  10. Robert Grosseteste's colours

    CERN Document Server

    Sparavigna, Amelia Carolina

    2013-01-01

    Here I am proposing a translation and discussion of the De Colore, one of the short scientific treatises written by Robert Grosseteste. In this very short treatise of the mid-1220s, Grosseteste continued the discussion on light and colours he started in the De Iride. He describes two manners of counting colours: one gives an infinity of tones, the other counts seven colours. In both cases, colours are created by the purity or impurity of the transparent medium when light is passing through it. This medieval framework survived until Newton's experiments with prisms.

  11. Colour and Organization Studies

    DEFF Research Database (Denmark)

    Beyes, Timon

    2016-01-01

    Colour is inescapable. It fills and forms the world, shaping what can be felt and known, desired and expressed. It thus becomes social technology and organizational tool. At the same time, however, colour betrays, undermines and subverts the attempts to manage it. Based on an understanding...... of colour as aesthetic force and medium of transformation, the essay presents a montage of scenes that set up encounters with what colour does: how it affects organization, and how it is affected by organization; how it organizes what is given to perception, knowledge and organization itself, and how...

  12. Colourful FKS subtraction

    CERN Document Server

    Frixione, Stefano

    2011-01-01

    I formulate in a colour-friendly way the FKS method for the computation of QCD cross sections at the next-to-leading order accuracy. This is achieved through the definition of subtraction terms for squared matrix elements, constructed with single colour-dressed or pairs of colour-ordered amplitudes. The latter approach relies on the use of colour flows, is exact to all orders in $N$, and is thus particularly suited to being organized as a systematic expansion in 1/N.

  13. Graph Colouring Algorithms

    DEFF Research Database (Denmark)

    Husfeldt, Thore

    2015-01-01

    This chapter presents an introduction to graph colouring algorithms. The focus is on vertex-colouring algorithms that work for general classes of graphs with worst-case performance guarantees in a sequential model of computation. The presentation aims to demonstrate the breadth of available...

  14. Graph colouring algorithms

    OpenAIRE

    Husfeldt, Thore

    2015-01-01

    This chapter presents an introduction to graph colouring algorithms. The focus is on vertex-colouring algorithms that work for general classes of graphs with worst-case performance guarantees in a sequential model of computation. The presentation aims to demonstrate the breadth of available techniques and is organized by algorithmic paradigm.

  15. Colour and Organization Studies

    DEFF Research Database (Denmark)

    Beyes, Timon

    2016-01-01

    of colour as aesthetic force and medium of transformation, the essay presents a montage of scenes that set up encounters with what colour does: how it affects organization, and how it is affected by organization; how it organizes what is given to perception, knowledge and organization itself, and how...

  16. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue ...

  17. The colours of CERN

    CERN Document Server

    Laëtitia Pedroso

    2010-01-01

    Would you move into an office painted in a colour you hate? As we all know, taste in colour is individual. Thanks to the establishment of a new Painting Charter, conflicting opinions will be unified.   The four new paint colours established in the Painting Charter. There were many reasons behind the creation of the Painting Charter by the GS SEM Department. Unlike many companies, CERN has not until now regulated which colours can be used inside buildings. With many nationalities passing through CERN, tastes tend to differ: northern countries usually prefer colder colours, while southern countries seem to prefer warm colours. It’s not hard to imagine how quickly we could make a rainbow! In addition, whenever an office needs to be repainted, it can be difficult to find exactly the same colour. This results in entire walls being repainted, which increases the cost. If – by chance – the original colour is found, it could be out of stock. While ...

  18. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been......Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new...

  19. Computational colour science using MATLAB

    CERN Document Server

    Westland, Stephen; Cheung, Vien

    2012-01-01

    Computational Colour Science Using MATLAB 2nd Edition offers a practical, problem-based approach to colour physics. The book focuses on the key issues encountered in modern colour engineering, including efficient representation of colour information, Fourier analysis of reflectance spectra and advanced colorimetric computation. Emphasis is placed on the practical applications rather than the techniques themselves, with material structured around key topics. These topics include colour calibration of visual displays, computer recipe prediction and models for colour-appearance prediction. Each t

  20. Effects of Memory Colour on Colour Constancy for Unknown Coloured Objects

    Directory of Open Access Journals (Sweden)

    Jeroen J M Granzier

    2012-04-01

    Full Text Available The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination—colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes—one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug. All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects.

  1. Unconventional colour vision.

    Science.gov (United States)

    Marshall, Justin; Arikawa, Kentaro

    2014-12-15

    Butterflies and stomatopods are certainly outliers in their unconventional colour sense and despite some similarities at first glance, in fact sample the world of colour very differently. In one way, butterflies are relatively conventional, possessing either tri-or tetrachromatic colour vision, then just adding one or several task-specific sub-mechanisms onto this. It is the stomatopods so far that have really pushed the boat out into a different colour vision mechanism. Over 400 million years of independent evolution they have arrived at a solution with more in common with the way a satellite sensor examines the colours of the earth than other animals. Remember, however, that unconventional colour vision is not just the realm of the serially polychromatic. Apparently waterfleas with four classes of spectral receptors living in ponds operate a task-specific spectral sense with no need, or indeed neural processing power, to construct a complex discriminatory mechanism. It seems they have the butterfly added-extra set without the more complex comparative chromatic mechanisms, although in truth, conclusive behavioural proof is lacking. Behavioural observation of colour vision in the ecological context of each animal is vital before making the distinction between conventional and unconventional. Just counting spectral sensitivities is never enough.

  2. Adaptive colouration in amphibians.

    Science.gov (United States)

    Rudh, Andreas; Qvarnström, Anna

    2013-01-01

    Amphibians, i.e. salamanders, frogs and caecilians show a wide range of bright colours in combination with contrasting patterns. There is variation among species, populations and also within species and populations. Furthermore, individuals often change colours during developmental stages or in response to environmental factors. This extraordinary variation means that there are excellent opportunities to test hypotheses of the adaptive significance of colours using amphibian species as models. We review the present view of functions of colouration in amphibians with the main focus on relatively unexplored topics. Variation in colouration has been found to play a role in thermoregulation, UV protection, predator avoidance and sexual signalling. However, many proposed cases of adaptive functions of colouration in amphibians remain virtually scientifically unexplored and surprisingly few genes influencing pigmentation or patterning have been detected. We would like to especially encourage more studies that take advantage of recent developments in measurement of visual properties of several possible signalling receivers (e.g. predators, competitors or mates). Future investigations on interactions between behaviour, ecology and vision have the potential to challenge our current view of the adaptive function of colouration in amphibians.

  3. Plasmonic colour laser printing

    DEFF Research Database (Denmark)

    Zhu, Xiaolong; Vannahme, Christoph; Højlund-Nielsen, Emil

    2016-01-01

    -beam lithography (EBL) or focused ion beam (FIB), both expensive and not scalable processes that are not suitable for post-processing customization. Here we show a method of colour printing on nanoimprinted plasmonic metasurfaces using laser post-writing. Laser pulses induce transient local heat generation...... that leads to melting and reshaping of the imprinted nanostructures. Depending on the laser pulse energy density, different surface morphologies that support different plasmonic resonances leading to different colour appearances can be created. Using this technique we can print all primary colours...

  4. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

  5. Evaluation of a wearable tele-echography robot system: FASTele in a vehicle using a mobile network.

    Science.gov (United States)

    Ito, Keiichiro; Tsuruta, Koichi; Sugano, Shigeki; Iwata, Hiroyasu

    2011-01-01

    This paper shows the focused assessment with sonography for trauma (FAST) performance of a wearable tele-echography robot system we have developed that we call "FASTele". FAST is a first-step way of assessing the injury severity of patients suffering from internal bleeding who may be some time away from hospital treatment. So far, we have only verified our system's effectiveness under constantly wired network conditions. To determine its FAST performance within an emergency vehicle, we extended it to a WiMAX mobile network and performed experiments on it. Experiment results showed that paramedics could attach the system to FAST areas on a patient's body on the basis of the attaching position and procedure. We also assessed echo images to confirm that the system is able to extract the echo images required for FAST under maximum vehicle acceleration.

  6. Distance-constrained grid colouring

    Directory of Open Access Journals (Sweden)

    Aszalós László

    2016-06-01

    Full Text Available Distance-constrained colouring is a mathematical model of the frequency assignment problem. This colouring can be treated as an optimization problem so we can use the toolbar of the optimization to solve concrete problems. In this paper, we show performance of distance-constrained grid colouring for two methods which are good in map colouring.

  7. Eat by Colour

    Institute of Scientific and Technical Information of China (English)

    David Heber; 谢琼

    2004-01-01

    <正> COLOUR is the key to good nutrition. Yet what colour is an increasing number of people’s diet? Beige.As a physician who has studied nutrition and cancer prevention for more than 20 years, I believe that bland diets actually account for the most common diseases, including heart disease, cancer and what I call diabesity-a booming epidemic of obesity and diabetes.

  8. Game Coloured Petri Nets

    DEFF Research Database (Denmark)

    Westergaard, Michael

    2006-01-01

    This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachabilit......, and not controllable by the system itself, or they are part of the system itself and therefore we need not worry about them)....

  9. Accurate Colour Reproduction in Prepress

    Directory of Open Access Journals (Sweden)

    Ákos Borbély

    2008-06-01

    Full Text Available The adjustment of colour to achieve an acceptable match between the displayed(soft copy and printed (hard copy document is an important task in prepress. In order toachieve such match colour management systems are used, these systems implementstandards established by the International Colour Consortium (ICC.A key step of the colour management process is the calibration of display and outputdevices, the definition of the relationship between the native colour space of the device anda standard device-independent colour space. In this work the usability of the ICC colourmanagement standard was investigated in case of flat panel LCD display calibration.

  10. Colour detection thresholds in faces and colour patches.

    Science.gov (United States)

    Tan, Kok Wei; Stephen, Ian D

    2013-01-01

    Human facial skin colour reflects individuals' underlying health (Stephen et al 2011 Evolution & Human Behavior 32 216-227); and enhanced facial skin CIELab b* (yellowness), a* (redness), and L* (lightness) are perceived as healthy (also Stephen et al 2009a International Journal of Primatology 30 845-857). Here, we examine Malaysian Chinese participants' detection thresholds for CIELab L* (lightness), a* (redness), and b* (yellowness) colour changes in Asian, African, and Caucasian faces and skin coloured patches. Twelve face photos and three skin coloured patches were transformed to produce four pairs of images of each individual face and colour patch with different amounts of red, yellow, or lightness, from very subtle (deltaE = 1.2) to quite large differences (deltaE = 9.6). Participants were asked to decide which of sequentially displayed, paired same-face images or colour patches were lighter, redder, or yellower. Changes in facial redness, followed by changes in yellowness, were more easily discriminated than changes in luminance. However, visual sensitivity was not greater for redness and yellowness in nonface stimuli, suggesting red facial skin colour special salience. Participants were also significantly better at recognizing colour differences in own-race (Asian) and Caucasian faces than in African faces, suggesting the existence of cross-race effect in discriminating facial colours. Humans' colour vision may have been selected for skin colour signalling (Changizi et al 2006 Biology Letters 2 217-221), enabling individuals to perceive subtle changes in skin colour, reflecting health and emotional status.

  11. Morphological patterns and their colour.

    Science.gov (United States)

    Dadam, James; Albertazzi, Liliana; Da Pos, Osvaldo; Canal, Luisa; Micciolo, Rocco

    2012-04-01

    This study analyzed qualitative aspects in perception, particularly the relationship between morphological aspects of biological shapes and colour. The experiment reported by the study assessed the functional relation between shape and colour and, in particular, the relations among the patterns of shapes appearing in perceptual configurations, as well as certain characteristics of colour. Participants were shown 32 natural images and were asked to match them with a colour. The results indicated that some figures were more frequently associated (positively or negatively) with some colours instead of others. Type of shape, texture, and three-dimensionality were important elements in the participants' choices. Rounded figures and non-holed figures had positive matches with red; elongated figures were associated with colours between blue and green; and holed figures showed positive matches with colours between green and yellow. Type of shape and texture also exhibited a relationship with the warmth of the colour.

  12. ATLAS Colouring Book

    CERN Multimedia

    Anthony, Katarina

    2016-01-01

    The ATLAS Experiment Colouring Book is a free-to-download educational book, ideal for kids aged 5-9. It aims to introduce children to the field of High-Energy Physics, as well as the work being carried out by the ATLAS Collaboration.

  13. Coloured Petri Nets

    CERN Document Server

    Jensen, Kurt

    2009-01-01

    Coloured Petri Nets (CPN) is a graphical language for modelling and validating concurrent and distributed systems, and other systems in which concurrency plays a major role. This book introduces the constructs of the CPN modelling language and presents the related analysis methods. It provides a comprehensive road map for the practical use of CPN.

  14. Colour Reconnection at LEPII

    CERN Document Server

    Abreu, P

    2001-01-01

    The preliminary results on the search of colour reconnection effects (CR) from the four experiments at LEP, Aleph, Delphi, L3 and Opal, are reviewed. Extreme models are excluded by studies of standard variables, and on going studies of a method first suggested by L3, the particle flow method, are yet inconclusive.

  15. Colour, vision and ergonomics.

    Science.gov (United States)

    Pinheiro, Cristina; da Silva, Fernando Moreira

    2012-01-01

    This paper is based on a research project - Visual Communication and Inclusive Design-Colour, Legibility and Aged Vision, developed at the Faculty of Architecture of Lisbon. The research has the aim of determining specific design principles to be applied to visual communication design (printed) objects, in order to be easily read and perceived by all. This study target group was composed by a selection of socially active individuals, between 55 and 80 years, and we used cultural events posters as objects of study and observation. The main objective is to overlap the study of areas such as colour, vision, older people's colour vision, ergonomics, chromatic contrasts, typography and legibility. In the end we will produce a manual with guidelines and information to apply scientific knowledge into the communication design projectual practice. Within the normal aging process, visual functions gradually decline; the quality of vision worsens, colour vision and contrast sensitivity are also affected. As people's needs change along with age, design should help people and communities, and improve life quality in the present. Applying principles of visually accessible design and ergonomics, the printed design objects, (or interior spaces, urban environments, products, signage and all kinds of visually information) will be effective, easier on everyone's eyes not only for visually impaired people but also for all of us as we age.

  16. Plasmonic colour laser printing

    DEFF Research Database (Denmark)

    Zhu, Xiaolong; Vannahme, Christoph; Højlund-Nielsen, Emil

    2016-01-01

    -beam lithography (EBL) or focused ion beam (FIB), both expensive and not scalable processes that are not suitable for post-processing customization. Here we show a method of colour printing on nanoimprinted plasmonic metasurfaces using laser post-writing. Laser pulses induce transient local heat generation...

  17. The Metric of Colour Space

    DEFF Research Database (Denmark)

    Gravesen, Jens

    2015-01-01

    The space of colours is a fascinating space. It is a real vector space, but no matter what inner product you put on the space the resulting Euclidean distance does not correspond to human perception of difference between colours. In 1942 MacAdam performed the first experiments on colour matching ...

  18. Colour displays for categorical images

    NARCIS (Netherlands)

    Glasbey, C.; Heijden, van der G.W.A.M.; Toh, V.F.K.; Gray, A.J.

    2007-01-01

    We propose a method for identifying a set of colours for displaying 2D and 3D categorical images when the categories are unordered labels. The principle is to find maximally distinct sets of colours. We either generate colours sequentially, to maximize the dissimilarity or distance between a new col

  19. Apendicitis epiploica primaria y hallazgos de la ecografía Primary epiploic appendicitis and echography findings

    Directory of Open Access Journals (Sweden)

    Orestes Noel Mederos Curbelo

    2010-03-01

    Full Text Available Se presenta el caso de una mujer de 55 años que presentaba dolor abdominal agudo localizado en el cuadrante inferior derecho, de 12 h de evolución, leucocitosis y reacción peritoneal. La ecografía abdominal fue indicativa de una presunta epiploitis, pero la intensidad y persistencia del dolor determinaron la intervención quirúrgica. La apendicitis aguda epiploica es una afección infrecuente pero debe sospecharse ante el dolor agudo en los cuadrantes abdominales inferiores, y la imagenología es fundamental para el diagnostico preoperatorio.This is the case of a woman aged 55 presenting with localized acute abdominal pain in right inferior quadrant of 12 hours of course, leukocytosis and peritoneal reaction. The abdominal echography findings showed a supposed epiploitis but the pain intensity and persistence determined the surgical intervention. Epiploic acute appendicitis is a infrequent affection that must to be suspected in case of acute pain in inferior abdominal quadrants and imaging studies are essential for preoperative diagnosis.

  20. Hue-specific colour memory impairment in an individual with intact colour perception and colour naming.

    Science.gov (United States)

    Jakobson, L S; Pearson, P M; Robertson, B

    2008-01-15

    Cases of hue-selective dyschomatopsias, together with the results of recent optical imaging studies [Xiao, Y., Casti, A. R. R., Xiao, J., & Kaplan, E. (2006). A spatially organized representation of colour in macaque primary visual cortex. Perception, 35, ECVP Abstract Supplement; Xiao, Y., Wang, Y., & Felleman, D. J. (2003). A spatially organized representation of colour in macaque cortical area V2. Nature, 421, 535-539], have provided support for the idea that different colours are processed in spatially distinct regions of extrastriate cortex. In the present report, we provide evidence suggesting that a similar, but distinct, map may exist for representations of colour in memory. This evidence comes from observations of a young woman (QP) who demonstrates an isolated deficit in colour memory secondary to a concussive episode. Despite having normal colour perception and colour naming skills, and above-average memory skills in other domains, QP's ability to recall visually encoded colour information over short retention intervals is dramatically impaired. Her long-term memory for colour and her colour imagery skills are also abnormal. Surprisingly, however, these impairments are not seen with all hues; specifically, her ability to remember or imagine blue shades is spared. This interesting case contributes to the literature suggesting that colour perception, naming, and memory can be clinically dissociated, and provides insights into the organization of colour information in memory.

  1. Supervised Object Class Colour Normalisation

    DEFF Research Database (Denmark)

    Riabchenko, Ekatarina; Lankinen, Jukka; Buch, Anders Glent;

    2013-01-01

    Colour is an important cue in many applications of computer vision and image processing, but robust usage often requires estimation of the unknown illuminant colour. Usually, to obtain images invariant to the illumination conditions under which they were taken, color normalisation is used....... In this work, we develop a such colour normalisation technique, where true colours are not important per se but where examples of same classes have photometrically consistent appearance. This is achieved by supervised estimation of a class specic canonical colour space where the examples have minimal variation...

  2. Annotating Coloured Petri Nets

    DEFF Research Database (Denmark)

    Lindstrøm, Bo; Wells, Lisa Marie

    2002-01-01

    Coloured Petri nets (CP-nets) can be used for several fundamentally different purposes like functional analysis, performance analysis, and visualisation. To be able to use the corresponding tool extensions and libraries it is sometimes necessary to include extra auxiliary information in the CP-ne...... a certain use of the CP-net. We define the semantics of annotations by describing a translation from a CP-net and the corresponding annotation layers to another CP-net where the annotations are an integrated part of the CP-net....... a method which makes it possible to associate auxiliary information, called annotations, with tokens without modifying the colour sets of the CP-net. Annotations are pieces of information that are not essential for determining the behaviour of the system being modelled, but are rather added to support...

  3. The Colours of Smell

    OpenAIRE

    Moeran, Brian

    2011-01-01

    This paper examines perfume advertising within the overall context of theoretical approaches to the study of smell. Pointing out that smell is marked by a paucity of language, it proceeds to examine how smell is represented in perfume advertisements. Based on an analysis of more than 250 ads worldwide, the paper asks if there are any consistent relations between language, colours and smell materials, as well as between models’ poses, seasons, and classes of perfume (floral, oriental, woody, a...

  4. Evaluation of the dosimetry impact of the MRI and bidimensional endorectal echography fusion for the prostate brachytherapy; Evaluation de l'impact dosimetrique de la fusion d'IRM et d'echographie endorectale bidimensionnelle pour les curietherapies de prostate

    Energy Technology Data Exchange (ETDEWEB)

    Fourneret, P.; Gastaldo, J.; Giraud, J.Y.; Bolla, M. [Hopital Michallon, Service de Radiotherapie-Oncologie, 38 - Grenoble (France); Daanen, V.; Troccaz, J. [Laboratoire TIMC/GMCAO, CNRS UMR 5525, 38 - Grenoble (France); Descotes, J.L. [Hopital Michallon, Service d' Urologie, 38 - Grenoble (France); Collomb, D. [Hopital Michallon, Service Radiologie, 38 - Grenoble (France)

    2006-11-15

    The volume modifications got by the echography-MRI fusion lead to significant modifications of the D90 (dose received by 90% of the prostate) and the prostate volume receiving as less as 160 Gy, on showing as a majority a lower value. It is explained by a bad visualisation of the base and apex in bidimensional echography. However, the D90 is always in the expected interval 160-180 Gy. For one patient, an important area of under dosage is at the apex level. The study of modifications of the dose-volume histogram on the rectum and urethra are the objectives of the year to come. These two organs are considered as being high risk and their evaluation should have a significant impact on our dosimetric approach. (N.C.)

  5. Usability and performance of a wearable tele-echography robot for focused assessment of trauma using sonography.

    Science.gov (United States)

    Ito, Keiichiro; Sugano, Shigeki; Takeuchi, Ryohei; Nakamura, Kyota; Iwata, Hiroyasu

    2013-02-01

    Focused Assessment with Sonography for Trauma (FAST) is widely used as a first lifesaving step for patients suffering from internal bleeding. Because it may take a long time to transport such patients to a hospital, a wearable and portable tele-echography robot that a paramedic can attach to the patient has been developed. In the current study, experiments were conducted to evaluate the usability and performance of attached FAST. The proposed robot must be attached to 4 areas to perform FAST. The time required for attachment and the positions of attachment completed by 9 non-medical staff members, as well as the time it took for the FAST to reach a medical doctor, were measured. The echo images obtained when the patient's body was in motion were evaluated by a medical doctor. The robot could be attached to all 4 areas within approximately 5min, and the maximum gap was 4.8cm. This indicates that a paramedic who has received training in emergency medical care should be able to attach the robot to a patient quickly and accurately. Additionally, it was confirmed that the robot could be used to complete FAST under a doctor's control within 9min and that the extracted echo images were suitable for FAST. A comparison of the results with current ambulance transportation time confirmed that FAST could be completed approximately 14min before the patient reached the hospital. The results of the current study indicate that the robot is worth using, is suitable for FAST, and will be effective in emergency medical care.

  6. Nonrepetitive Colouring via Entropy Compression

    CERN Document Server

    Dujmović, Vida; Wood, David R

    2011-01-01

    A vertex colouring of a graph is \\emph{nonrepetitive} if there is no path whose first half receives the same sequence of colours as the second half. A graph is nonrepetitively $k$-choosable if given lists of at least $k$ colours at each vertex, there is a nonrepetitive colouring such that each vertex is coloured from its own list. It is known that every graph with maximum degree $\\Delta$ is $c\\Delta^2$-choosable, for some constant $c$. We prove this result with $c=4$. We then prove that every subdivision of a graph with sufficiently many division vertices per edge is nonrepetitively 6-choosable. The proofs of both these results are based on the Moser-Tardos entropy-compression method, and a recent extension by Grytczuk, Kozik and Micek for the nonrepetitive choosability of paths. Finally, we prove that every graph with pathwidth $k$ is nonrepetitively ($2k^2+6k+1$)-colourable.

  7. Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1991-01-01

    This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...... use of CP-nets — because it means that the function representation and the translations (which are a bit mathematically complex) no longer are parts of the basic definition of CP-nets. Instead they are parts of the invariant method (which anyway demands considerable mathematical skills...

  8. Theory of colours

    CERN Document Server

    Goethe, Johann Wolfgang von

    2006-01-01

    The wavelength theory of light and color had been firmly established by the time the great German poet published his Theory of Colours in 1810. Nevertheless, Goethe believed that the theory derived from a fundamental error, in which an incidental result was mistaken for a elemental principle. Far from affecting a knowledge of physics, he maintained that such a background would inhibit understanding. The conclusions Goethe draws here rest entirely upon his personal observations.This volume does not have to be studied to be appreciated. The author's subjective theory of colors permits him to spe

  9. Colours in Amish Quilts

    OpenAIRE

    Homlong, Siri

    2015-01-01

    The Amish religious movement have its roots in the Protestant Reformation in the 16th century. The Amish people are anabaptists and have strict rules for their way of life. They were persecuted in Europe and Amish groups emigrated to Pennsylvania. Today the most traditional part of the movement – the Old Amish People – lives in Lancaster County west of Philadelphia, USA. This paper describs a study of the colours in Old Amish Quilts, traditional Amish patchwork quilts used as bed covers. The ...

  10. Across light: through colour

    Science.gov (United States)

    Azevedo, Isabel; Richardson, Martin; Bernardo, Luis Miguel

    2012-03-01

    The speed at which our world is changing is reflected in the shifting way artistic images are created and produced. Holography can be used as a medium to express the perception of space with light and colour and to make the material and the immaterial experiments with optical and digital holography. This paper intends to be a reflection on the final product of that process surrounding a debate of ideas for new experimental methodologies applied to holographic images. Holography is a time-based medium and the irretrievable linear flow of time is responsible for a drama, unique to traditional cinematography. If the viewers move to left or right, they see glimpses of the next scene or the previous one perceived a second ago. This interaction of synthetic space arises questions such as: can we see, in "reality", two forms in the same space? Trying to answer this question, a series of works has been created. These concepts are embryonic to a series of digital art holograms and lenticulars technique's titled "Across Light: Through Colour". They required some technical research and comparison between effects from different camera types, using Canon IS3 and Sony HDR CX105.

  11. A colourful clock.

    Directory of Open Access Journals (Sweden)

    Hester C van Diepen

    2015-05-01

    Full Text Available Circadian rhythms are an essential property of life on Earth. In mammals, these rhythms are coordinated by a small set of neurons, located in the suprachiasmatic nuclei (SCN. The environmental light/dark cycle synchronizes (entrains the SCN via a distinct pathway, originating in a subset of photosensitive retinal ganglion cells (pRGCs that utilize the photopigment melanopsin (OPN4. The pRGCs are also innervated by rods and cones and, so, are both endogenously and exogenously light sensitive. Accumulating evidence has shown that the circadian system is sensitive to ultraviolet (UV, blue, and green wavelengths of light. However, it was unclear whether colour perception itself can help entrain the SCN. By utilizing both behavioural and electrophysiological recording techniques, Walmsley and colleagues show that multiple photic channels interact and enhance the capacity of the SCN to synchronize to the environmental cycle. Thus, entrainment of the circadian system combines both environmental irradiance and colour information to ensure that internal and external time are appropriately aligned.

  12. A colourful clock.

    Science.gov (United States)

    van Diepen, Hester C; Foster, Russell G; Meijer, Johanna H

    2015-05-01

    Circadian rhythms are an essential property of life on Earth. In mammals, these rhythms are coordinated by a small set of neurons, located in the suprachiasmatic nuclei (SCN). The environmental light/dark cycle synchronizes (entrains) the SCN via a distinct pathway, originating in a subset of photosensitive retinal ganglion cells (pRGCs) that utilize the photopigment melanopsin (OPN4). The pRGCs are also innervated by rods and cones and, so, are both endogenously and exogenously light sensitive. Accumulating evidence has shown that the circadian system is sensitive to ultraviolet (UV), blue, and green wavelengths of light. However, it was unclear whether colour perception itself can help entrain the SCN. By utilizing both behavioural and electrophysiological recording techniques, Walmsley and colleagues show that multiple photic channels interact and enhance the capacity of the SCN to synchronize to the environmental cycle. Thus, entrainment of the circadian system combines both environmental irradiance and colour information to ensure that internal and external time are appropriately aligned.

  13. Linguistic determinants of word colouring in grapheme-colour synaesthesia.

    Science.gov (United States)

    Simner, Julia; Glover, Louise; Mowat, Alice

    2006-02-01

    Previous studies of grapheme-colour synaesthesia have suggested that words tend to be coloured by their initial letter or initial vowel (e.g., Baron-Cohen et al., 1993; Ward et al., 2005). We examine this assumption in two ways. First, we show that letter position and syllable stress have been confounded, such that the initial letters of a word are often in stressed position (e.g., 'wo-man, 'ta-ble, 'ha-ppy). With participant JW, we separate these factors (e.g., with stress homographs such as 'con-vict vs. con-'vict) and show that the primary determinant of word colour is syllable stress, with only a secondary influence of letter position. We show that this effect derives from conceptual rather than perceptual stress, and that the effect is more prominent for synaesthetes whose words are coloured by vowels than by consonants. We examine, too, the time course of word colour generation. Slower colour naming occurs for spoken versus written stimuli, as we might expect from the additional requirement of grapheme conversion in the former. Reaction time data provide evidence, too, of incremental processing, since word colour is generated faster when the dominant grapheme is flagged early rather than late in the spoken word. Finally, we examine the role of non-dominant graphemes in word colouring and show faster colour naming when later graphemes match the dominant grapheme (e.g., ether) compared to when they do not (e.g., ethos). Taken together, our findings suggest that words are coloured incrementally by a process of competition between constituent graphemes, in which stressed graphemes and word-initial graphemes are disproportionately weighted.

  14. Reversible colour change in Arthropoda.

    Science.gov (United States)

    Umbers, Kate D L; Fabricant, Scott A; Gawryszewski, Felipe M; Seago, Ainsley E; Herberstein, Marie E

    2014-11-01

    The mechanisms and functions of reversible colour change in arthropods are highly diverse despite, or perhaps due to, the presence of an exoskeleton. Physiological colour changes, which have been recorded in 90 arthropod species, are rapid and are the result of changes in the positioning of microstructures or pigments, or in the refractive index of layers in the integument. By contrast, morphological colour changes, documented in 31 species, involve the anabolism or catabolism of components (e.g. pigments) directly related to the observable colour. In this review we highlight the diversity of mechanisms by which reversible colour change occurs and the evolutionary context and diversity of arthropod taxa in which it has been observed. Further, we discuss the functions of reversible colour change so far proposed, review the limited behavioural and ecological data, and argue that the field requires phylogenetically controlled approaches to understanding the evolution of reversible colour change. Finally, we encourage biologists to explore new model systems for colour change and to engage scientists from other disciplines; continued cross-disciplinary collaboration is the most promising approach to this nexus of biology, physics, and chemistry.

  15. The brightness of colour.

    Directory of Open Access Journals (Sweden)

    David Corney

    Full Text Available BACKGROUND: The perception of brightness depends on spatial context: the same stimulus can appear light or dark depending on what surrounds it. A less well-known but equally important contextual phenomenon is that the colour of a stimulus can also alter its brightness. Specifically, stimuli that are more saturated (i.e. purer in colour appear brighter than stimuli that are less saturated at the same luminance. Similarly, stimuli that are red or blue appear brighter than equiluminant yellow and green stimuli. This non-linear relationship between stimulus intensity and brightness, called the Helmholtz-Kohlrausch (HK effect, was first described in the nineteenth century but has never been explained. Here, we take advantage of the relative simplicity of this 'illusion' to explain it and contextual effects more generally, by using a simple Bayesian ideal observer model of the human visual ecology. We also use fMRI brain scans to identify the neural correlates of brightness without changing the spatial context of the stimulus, which has complicated the interpretation of related fMRI studies. RESULTS: Rather than modelling human vision directly, we use a Bayesian ideal observer to model human visual ecology. We show that the HK effect is a result of encoding the non-linear statistical relationship between retinal images and natural scenes that would have been experienced by the human visual system in the past. We further show that the complexity of this relationship is due to the response functions of the cone photoreceptors, which themselves are thought to represent an efficient solution to encoding the statistics of images. Finally, we show that the locus of the response to the relationship between images and scenes lies in the primary visual cortex (V1, if not earlier in the visual system, since the brightness of colours (as opposed to their luminance accords with activity in V1 as measured with fMRI. CONCLUSIONS: The data suggest that perceptions

  16. Natural Blue Food Colour

    DEFF Research Database (Denmark)

    Roda-Serrat, Maria Cinta

    In recent years, there has been a growing tendency to avoid the use of artificial colorants and additives in food products, especially after some studies linked their consumption with behavioural changes in children. However, the incorporation of colorants from natural origin remains a challenge...... for food technologists, as these are typically less vivid and less stable than their synthetic alternatives. Regarding blue colorants, phycocyanins from cyanobacteria are currently in the spotlight as promising new natural blue colorants. Phycocyanins are proteins which blue colour results from...... the presence of the chromophore phycocyanobilin (PCB), a covalently attached linear tetrapyrrole. The applications of phycocyanins as food colorants are however limited, as they show poor stability in certain conditions of pH, light and temperature. Cleavage of PCB from the protein followed by careful product...

  17. Genetics of colouration in birds.

    Science.gov (United States)

    Roulin, Alexandre; Ducrest, Anne-Lyse

    2013-01-01

    Establishing the links between phenotype and genotype is of great importance for resolving key questions about the evolution, maintenance and adaptive function of phenotypic variation. Bird colouration is one of the most studied systems to investigate the role of natural and sexual selection in the evolution of phenotypic diversity. Given the recent advances in molecular tools that allow discovering genetic polymorphisms and measuring gene and protein expression levels, it is timely to review the literature on the genetics of bird colouration. The present study shows that melanin-based colour phenotypes are often associated with mutations at melanogenic genes. Differences in melanin-based colouration are caused by switches of eumelanin to pheomelanin production or by changes in feather keratin structure, melanoblast migration and differentiation, as well as melanosome structure. Similar associations with other types of colourations are difficult to establish, because our knowledge about the molecular genetics of carotenoid-based and structural colouration is quasi inexistent. This discrepancy stems from the fact that only melanin-based colouration shows pronounced heritability estimates, i.e. the resemblance between related individuals is usually mainly explained by genetic factors. In contrast, the expression of carotenoid-based colouration is phenotypically plastic with a high sensitivity to variation in environmental conditions. It therefore appears that melanin-based colour traits are prime systems to understand the genetic basis of phenotypic variation. In this context, birds have a great potential to bring us to new frontiers where many exciting discoveries will be made on the genetics of phenotypic traits, such as colouration. In this context, a major goal of our review is to suggest a number of exciting future avenues.

  18. Multi-coloured stereograms unveil two binocular colour mechanisms in human vision.

    Science.gov (United States)

    Erkelens, Casper J; van Ee, Raymond

    2002-04-01

    Two different colours, one presented to one eye and the other presented to the other eye, often create the impression of a third colour. This percept is known as binocular colour mixture. Here we use coloured stereograms to study binocular colour appearance. Vivid pastel colours are induced in monocular, achromatic patches, if these are placed in stereograms whose left and right images differ in colour. The build-up of the colours is slow and takes tens of seconds or even minutes in certain individuals. The induced colours remain visible during monocular viewing of the patch and decay gradually. The same colours are induced irrespective of whether the patches are placed in fusible or rivalrous stereograms. We show that these colour effects cannot be induced by monocular colour mechanisms, either alone or in combination with binocular colour mixing. We suggest that the colours are induced by a binocular feedback mechanism, which reduces colour differences between the colour appearances of two monocular images. Induced colours are not observed if the achromatic patches are binocular. However, induced colours are apparent if one switches to monocular viewing after prolonged binocular viewing of the binocular patches. This aftereffect suggests that binocular colour induction acts on the monocular representations of binocular images. We suggest that during binocular viewing the fast process of binocular colour mixing masks the changes in colour appearance produced by the much slower process of binocular colour induction.

  19. Colour reconnection in WW events

    CERN Document Server

    D'Hondt, J

    2003-01-01

    Preliminary results are presented for a measurement of the kappa parameter used in the JETSET SK-I model of colour reconnection in W /sup +/W/sup -/ to qq'qq' events at LEP2. An update on the investigation of colour reconnection effects in hadronic decays of W pairs, using the particle flow in DELPHI is presented. A second method is based on the observation that two different m/sub W/ estimators have different sensitivity to the parametrised colour reconnection effect. Hence the difference between them is an observable with information content about kappa. (6 refs).

  20. Colour anomia resulting from weakened short-term colour memory. A case study.

    Science.gov (United States)

    Davidoff, J B; Ostergaard, A L

    1984-06-01

    A patient exhibited marked colour anomia without object anomia, but was able to point to named colours. Five experiments were conducted to investigate his immediate colour memory. It was concluded that his colour anomia was the result of an impaired short-term memory deficit specific to colour. Temporary activation of specific entries in the colour lexicon enabled pointing and even naming to take place. A general model incorporating all forms of colour anomia is presented.

  1. Alternative to colour feature classification using colour contrast ocurrence matrix

    Science.gov (United States)

    Martínez, R. A.; Richard, N.; Fernandez, C.

    2015-04-01

    Texture discrimination was the second more important task studied after colour perception and characterization. Nevertheless, colour texture assessment and characterization was few studied and no vector processing was proposed to assess this important visual information. In this work we show the construction of a new vector that integrates fully the information of texture and color. This vector is based on Julesz psico-physics conjectures and the Haralick cooccurrence matrix. A colour texture image in the CIEL*a* b* colour space is characterizing in a 3D matrix, from which it is possible to visually some variations in chromaticity. The performance of this vector had evaluated in tasks of classification in front of other developments that mix the texture and colour information. The colour contrast occurrence matrix (C2O) has the best classification rates in three of the four image database evaluated as OUTEX, VISTEX, STEX and ALOT. C2O texture classification was evaluated in front of co-occurrence matrix (GLMC), run-length matrix (RLM) and local binary patterns (LBP) approaches.

  2. Optimal colour quality of LED clusters based on memory colours.

    Science.gov (United States)

    Smet, Kevin; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

    2011-03-28

    The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant.

  3. Colour Separation and Aversion

    Directory of Open Access Journals (Sweden)

    Sarah M Haigh

    2012-05-01

    Full Text Available Aversion to achromatic patterns is well documented but relatively little is known about discomfort from chromatic patterns. Large colour differences are uncommon in the natural environment and deviation from natural statistics makes images uncomfortable (Fernandez and Wilkins 2008, Perception, 37(7, 1098–113; Juricevic et al 2010, Perception, 39(7, 884–899. We report twelve studies documenting a linear increase in aversion to chromatic square-wave gratings as a function of the separation in UCS chromaticity between the component bars, independent of their luminance contrast. Two possible explanations for the aversion were investigated: (1 accommodative response, or (2 cortical metabolic demand. We found no correlation between chromaticity separation and accommodative lag or variance in lag, measured using an open-field autorefractor. However, near infrared spectroscopy of the occipital cortex revealed a larger oxyhaemoglobin response to patterns with large chromaticity separation. The aversion may be cortical in origin and does not appear to be due to accommodation.

  4. BRIEF REPORT: The colour relaxation equation

    Science.gov (United States)

    Xiaofei, Zhang; Jiarong, Li

    1996-03-01

    Colour diffusion in quark - gluon plasma (QGP) is investigated from the transport equations of QGP. The pure non-Abelian collision term describing the colour diffusion in QGP is obtained, the expression for colour relaxation time is derived and the physical picture of the colour diffusion in QGP is shown.

  5. A new universal colour image fidelity metric

    NARCIS (Netherlands)

    Toet, A.; Lucassen, M.P.

    2003-01-01

    We extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated colour space. The resulting colour image fidelity metric quantifies the distortion of a processed colour image relative to its original version. We evaluated the new colour image fi

  6. Structural colours through photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    McPhedran, R.C.; Nicorovici, N.A.; McKenzie, D.R.; Rouse, G.W.; Botten, L.C.; Welch, V.; Parker, A.R.; Wohlgennant, M.; Vardeny, V

    2003-10-01

    We discuss two examples of living creatures using photonic crystals to achieve iridescent colouration. The first is the sea mouse (Aphroditidae, Polychaeta), which has a hexagonal close packed structure of holes in its spines and lower-body felt, while the second is the jelly fish Bolinopsis infundibulum, which has an oblique array of high index inclusions in its antennae. We show by measurements and optical calculations that both creatures can achieve strong colours despite having access only to weak refractive index contrast.

  7. Colour Day: an innovative project

    CERN Document Server

    Staff Association

    2016-01-01

    This year, the Children’s Day-Care Centre (EVE) and School works on the theme of colours. Every class has their own project revolving around this common theme. The class of Claire, Sandrine and Nadia, introduced a monthly “Colour Day”. The objective of this day is to offer children different activities (arts and crafts, baking, etc.) designed around a specific colour. The children get a chance to decorate their classroom and learn in many different ways inspired by the colours blue, red, and many others. The parents are also called to contribute and invited to dress their children in the colour of the day. In September, we discovered the colour blue, in October it was time for red, and in mid-November yellow will brighten up our structure. Everyone plays along, making this a very festive day for us all. On Tuesday, 20 September, we saw the whole School turn blue! We were all dressed in blue and we made blue paintings, too! We made beautiful artwork inspired by artists like Ma...

  8. Colour, Luminance and Crowding

    Directory of Open Access Journals (Sweden)

    BJ Jennings

    2013-10-01

    Full Text Available Three experiments were performed to assess the effect backgrounds have on object discrimination. Experiment 1 investigated the discrimination of foveally presented Gaborised objects and non-objects with and without a surrounding background. Thresholds were obtained by modulating the Gabor patches in 7 different directions, either isolating the L-M, S-(L+M and L+M geniculate mechanisms, or stimulating these mechanisms in combination. The spacing between background Gabor elements and the object contour was chosen so as to not cause crowding, on the basis of previously published work with luminance stimuli. No differences were found between the Michelson contrasts required for threshold with or without a background, except when signals in the S-(L+M and L+M were combined. The signals were combined at an elevation of 30° in DKL colour space, which resulted in a mixture with a proportionally strong chromatic signal. Experiment 2 investigated this finding further using three background conditions: no background, a sparse background and a densely populated background. Object vs. non-object discrimination thresholds were obtained for the L+M and S-(L+M isolating directions, along with two conditions that combined them at DKL luminance elevations of 30° and 60°. In the 60° combination, the proportion of the chromatic signal was lower than in the 30° combination. Thresholds were found to be largely stable across chromatic and luminance conditions and background class, again with the exception of the combination at 30° elevation. The final experiment examined Gabor orientation discrimination over the same conditions as experiment 2 using a classical crowding paradigm, with a peripheral target and a set of three target-flanker separations. Crowding was most pronounced in the 30° combination. We conclude that when S-(L+M signals above a certain level are combined with luminance signals, an increase in crowding results. This is likely to underlie the

  9. Colour Symbols in Mari Songs

    Directory of Open Access Journals (Sweden)

    Natalia Glukhova

    2016-06-01

    Full Text Available This article presents a system of colour symbols in Mari folk songs based on the results of a multifold investigation. The research was carried out with the help of a complex technique applied to 2100 songs from different song collections. Mari colour symbols have never before been the object of research. The process of investigation included several steps. The most important of these was the semantic analysis that helped to discern 2000 mentions of four main spectre colours as well as white, black, silver, and golden. Quantitative data evaluation singled out a dominant group by a dichotomous method, applying the principle of simple majority employed in mathematical statistics. The same technique divided the other colour symbols into complementary, auxiliary, and insignificant groups. The results of an investigation into ethnic symbology are also shown graphically. The main reconstructed meanings of colour in the analysed songs denote such emotions as joy, wonder, astonishment, grief, melancholy, some aesthetic ideals, ethical vices, as well as people’s character and appearance.

  10. The colour of gender stereotyping.

    Science.gov (United States)

    Cunningham, Sheila J; Macrae, C Neil

    2011-08-01

    Despite legislative attempts to eliminate gender stereotyping from society, the propensity to evaluate people on the basis of their sex remains a pernicious social problem. Noting the critical interplay between cultural and cognitive factors in the establishment of stereotypical beliefs, the current investigation explored the extent to which culturally transmitted colour-gender associations (i.e., pink is for girls, blue is for boys) set the stage for the automatic activation and expression of gender stereotypes. Across six experiments, the results demonstrated that (1) consumer choice for children's goods is dominated by gender-stereotyped colours (Experiment 1); (2) colour-based stereotypic associations guide young children's behaviour (Experiment 2); (3) colour-gender associations automatically activate associated stereotypes in adulthood (Experiments 3-5); and (4) colour-based stereotypic associations bias impressions of male and female targets (Experiment 6). These findings indicate that, despite prohibitions against stereotyping, seemingly innocuous societal practices may continue to promote this mode of thought. ©2011 The British Psychological Society.

  11. Digieye Application In Cotton Colour Measurement

    Directory of Open Access Journals (Sweden)

    Matusiak Małgorzata

    2015-06-01

    Full Text Available Colour is one of the most important properties of cotton raw materials. It helps in determining and classifying the quality of fibres according to the Universal Cotton Standards. Organoleptic and instrumental techniques are applied to assess the color of cotton. Worldwide, the colour parameters of cotton are measured by the High Volume Instrument (HVI, which provides information on reflectance (Rd and yellowness (+b that is specific for cotton, but are not the typical and globally recognized colour characteristics. Usually, worldwide, the colour of textile products and other goods is assessed utilizing the spectrophotometer, which provides the colour data that is widely recognized and accepted by the CIE L*a*b* colour space. This paper discusses utilizing the DigiEye system to measure the colour parameters of cotton samples and compares the results with the colour parameters from the HVI.

  12. Special Section on Coloured Petri Nets

    DEFF Research Database (Denmark)

    1998-01-01

    Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications.......Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications....

  13. Phenomenology of high colour fermions

    Energy Technology Data Exchange (ETDEWEB)

    Lust, D.; Streng, K.H.; Papantonopoulos, E.; Zoupanos, G.

    1986-04-28

    We present the phenomenological consequences of a dynamical scenario for electroweak symmetry breaking and generation of fermion masses, involving the presence of fermions which transform under high colour representations. Particular emphasis is given to the predictions for rare processes and to the possible signals in present and future machines. (orig.).

  14. Chromomagnetic catalysis of colour superconductivity

    CERN Document Server

    Zhukovskij, V C; Klimenko, K G; Ehbert, D

    2001-01-01

    The effect of the chromomagnetic field on the phase structure of the Namby - Jona-Lasinio expanded model with two quarks aromas is studied. It is shown that certain types of the chromomagnetic fields induce spontaneous violation of the colour, chiral or both symmetries simultaneously, depending on the ratio between the quarks interaction constants in the q-barq- and qq-channels

  15. Skills Underlying Coloured Progressive Matrices

    Science.gov (United States)

    Kirby, J. R.; Das, J. P.

    1978-01-01

    Raven's Coloured Progressive Matrices and a battery of ability tests were administered to a sample of 104 male fourth graders for purposes of investigating the relationships between 2 previously identified subscales of the Raven and the ability tests. Results indicated use of a spatial strategy and to a lesser extent, use of reasoning, indicating…

  16. Colour reconnection at LEP2

    CERN Document Server

    Abreu, P

    2002-01-01

    The preliminary results on the search of colour reconnection effects (CR) from the four experiments at LEP, ALEPH, DELPHI, L3 and OPAL, are reviewed. Extreme models are excluded by studies of standard variables, and on going studies of a method first suggested by L3, the particle flow method (D. Duchesneau, (2001)), are yet inconclusive. (22 refs).

  17. The "Human Colour" Crayon: Investigating the Attitudes and Perceptions of Learners Regarding Race and Skin Colour

    Science.gov (United States)

    Alexander, Neeske; Costandius, Elmarie

    2017-01-01

    Some coloured and black learners in South Africa use a light orange or pink crayon to represent themselves in art. Many learners name this colour "human colour" or "skin colour". This is troublesome, because it could reflect exclusionary ways of representing race in images and language. This case study, conducted with two…

  18. Search for Colour Singlet and Colour Reconnection Effects in Hadronic Z Decays at LEP

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, F; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Novák, T; Nowak, H; Ofierzynski, R A; Organtini, G; Pal, I; Palomares, C; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Schäfer, C; Shchegelskii, V; Schopper, Herwig Franz; Schotanus, D J; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, Q; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2004-01-01

    A search is performed in symmetric 3-jet hadronic Z decay events for evidence of colour singlet production or colour reconnection effects. Asymmetries in the angular separation of particles are found to be sensitive indicators of such effects. Upper limits on the level of colour singlet production and colour reconnection effects are established for a variety of models.

  19. Biological Components of Colour Preference in Infancy

    Science.gov (United States)

    Franklin, Anna; Bevis, Laura; Ling, Yazhu; Hurlbert, Anya

    2010-01-01

    Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S-(L+M) ("blue-yellow") and L-M ("red-green") cone-opponent contrast channels ( Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in…

  20. Colour in the eyes of insects

    NARCIS (Netherlands)

    Stavenga, D.G.

    Many insect species have darkly coloured eyes, but distinct colours or patterns are frequently featured. A number of exemplary cases of flies and butterflies are discussed to illustrate our present knowledge of the physical basis of eye colours, their functional background, and the implications for

  1. -Colour even Self-Inverse Compositions

    Indian Academy of Sciences (India)

    Yu-hong Guo

    2010-02-01

    An -colour even self-inverse composition is defined as an -colour self-inverse composition with even parts. In this paper, we get generating functions, explicit formulas and recurrence formulas for -colour even self-inverse compositions. One new binomial identity is also obtained.

  2. Colour in the eyes of insects

    NARCIS (Netherlands)

    Stavenga, D.G.

    2002-01-01

    Many insect species have darkly coloured eyes, but distinct colours or patterns are frequently featured. A number of exemplary cases of flies and butterflies are discussed to illustrate our present knowledge of the physical basis of eye colours, their functional background, and the implications for

  3. Biological Components of Colour Preference in Infancy

    Science.gov (United States)

    Franklin, Anna; Bevis, Laura; Ling, Yazhu; Hurlbert, Anya

    2010-01-01

    Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S-(L+M) ("blue-yellow") and L-M ("red-green") cone-opponent contrast channels ( Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in…

  4. Colour Vision Deficiency and Physics Teaching

    Science.gov (United States)

    Maule, Louise; Featonby, David

    2016-01-01

    1 in 12 males suffer from some form of colour vision deficiency (CVD) which in the present colour dominated world of education presentation can be a severe disadvantage. Although aware of "colourblindness" most teachers make little or no adjustment for these pupils for whom tasks may be more difficult. This article examines colour vision…

  5. Synaesthetic Colours Can Behave More like Recalled Colours, as Opposed to Physical Colours that Can Be Seen

    Directory of Open Access Journals (Sweden)

    Derek H. Arnold

    2011-05-01

    Full Text Available Grapheme-color synaesthesia is an atypical condition characterized by coloured sensations when reading achromatic text. Different forms have been characterized, but this is somewhat controversial. In associative grapheme-colour synaesthesia, written graphemes can automatically trigger a sensation of colour in the ‘mind's eye’, but hearing the name of a grapheme does not. This allowed us explore the precision with which synaesthetes match triggered synaesthetic colours across separate presentations, versus the precision for recalled experiences cued by spoken graphemes. We recorded CIE coordinates, and found that matches for triggered sensations were equally variable relative to recalled experiences. To ensure this was not due to insensitivity of our apparatus, we next had synaesthetes and age-matched controls either match the colour of a circular patch while they could see it, or from memory after it had disappeared. Both synaesthetes and controls were more variable when matching from memory, and synaesthetes were more precise when matching colour hue, but not brightness. Interestingly, the variance of synaesthetes' recalled matches in this experiment matched that associated with synaesthetic colours in the first experiment. Overall, our data suggests that, for associative grapheme-colour synaesthetes, synaesthetic colours behave more like recalled colours, as opposed to physical colours that can be seen.

  6. The colour of architecture. Past and present

    Directory of Open Access Journals (Sweden)

    Veronica Maria Zybaczynski

    2013-12-01

    Full Text Available Colour has accompanied man throughout time since the beginnings, the primitive man used colour to paint drawings in caves, so the relationship between man and colour was, and still is, one of the closest. In architecture, colour swung between the magic, ritualic role and aesthetics, between outside and inside, scoring or reinterpreting in every step new facets and meanings. This article is a brief overview of the main aspects of this evolution, from the prehistoric times to the present with an emphasis on the relationship between the colour and the architectural composition.

  7. A STANDARDIZED LANTERN FOR TESTING COLOUR VISION.

    Science.gov (United States)

    Martin, L C

    1939-01-01

    A Lantern for lesting Colour-Vision is arranged to show test colours in pairs as in the Board of Trade Lantern. It is adapted to use electric light, and is standardized by stringent testing. The paper discusses the experiments and considerations which led to the formulation of the allowable tolerances in the transmission and colour co-ordinate specifications of the filters, the colour temperature of the lamps and so on. The results of tests on normal and colour-defective subjects are described.

  8. Characterisation of the n-colour printing process using the spot colour overprint model.

    Science.gov (United States)

    Deshpande, Kiran; Green, Phil; Pointer, Michael R

    2014-12-29

    This paper is aimed at reproducing the solid spot colours using the n-colour separation. A simplified numerical method, called as the spot colour overprint (SCOP) model, was used for characterising the n-colour printing process. This model was originally developed for estimating the spot colour overprints. It was extended to be used as a generic forward characterisation model for the n-colour printing process. The inverse printer model based on the look-up table was implemented to obtain the colour separation for n-colour printing process. Finally the real-world spot colours were reproduced using 7-colour separation on lithographic offset printing process. The colours printed with 7 inks were compared against the original spot colours to evaluate the accuracy. The results show good accuracy with the mean CIEDE2000 value between the target colours and the printed colours of 2.06. The proposed method can be used successfully to reproduce the spot colours, which can potentially save significant time and cost in the printing and packaging industry.

  9. Colour dependence of zodiacal light models

    Science.gov (United States)

    Giese, R. H.; Hanner, M. S.; Leinert, C.

    1973-01-01

    Colour models of the zodiacal light in the ecliptic have been calculated for both dielectric and metallic particles in the sub-micron and micron size range. Two colour ratios were computed, a blue ratio and a red ratio. The models with a size distribution proportional to s to the -2.5 power ds (where s is the particle radius) generally show a colour close to the solar colour and almost independent of elongation. Especially in the blue colour ratio there is generally no significant dependence on the lower cutoff size (0.1-1 micron). The main feature of absorbing particles is a reddening at small elongations. The models for size distributions proportional to s to the -4 power ds show larger departures from solar colour and more variation with model parameters. Colour measurements, including red and near infra-red, therefore are useful to distinguish between flat and steep size spectra and to verify the presence of slightly absorbing particles.

  10. Evolution of colour vision in mammals.

    Science.gov (United States)

    Jacobs, Gerald H

    2009-10-12

    Colour vision allows animals to reliably distinguish differences in the distributions of spectral energies reaching the eye. Although not universal, a capacity for colour vision is sufficiently widespread across the animal kingdom to provide prima facie evidence of its importance as a tool for analysing and interpreting the visual environment. The basic biological mechanisms on which vertebrate colour vision ultimately rests, the cone opsin genes and the photopigments they specify, are highly conserved. Within that constraint, however, the utilization of these basic elements varies in striking ways in that they appear, disappear and emerge in altered form during the course of evolution. These changes, along with other alterations in the visual system, have led to profound variations in the nature and salience of colour vision among the vertebrates. This article concerns the evolution of colour vision among the mammals, viewing that process in the context of relevant biological mechanisms, of variations in mammalian colour vision, and of the utility of colour vision.

  11. Colour application on mammography image segmentation

    Science.gov (United States)

    Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

    2017-09-01

    The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

  12. -Colour Self-Inverse Compositions

    Indian Academy of Sciences (India)

    Geetika Narang; A K Agarwal

    2006-08-01

    MacMahon’s definition of self-inverse composition is extended to -colour self-inverse composition. This introduces four new sequences which satisfy the same recurrence relation with different initial conditions like the famous Fibonacci and Lucas sequences. For these new sequences explicit formulas, recurrence relations, generating functions and a summation formula are obtained. Two new binomial identities with combinatorial meaning are also given.

  13. Colour Reconnection - Models and Tests

    CERN Document Server

    Christiansen, Jesper R

    2015-01-01

    Recent progress on colour reconnection within the Pythia framework is presented. A new model is introduced, based on the SU(3) structure of QCD and a minimization of the potential string energy. The inclusion of the epsilon structure of SU(3) gives a new baryon production mechanism and makes it possible simultaneously to describe hyperon production at both $e^+e^-$ and pp colliders. Finally, predictions for $e^+e^-$ colliders, both past and potential future ones, are presented.

  14. Colours sometimes count: awareness and bidirectionality in grapheme-colour synaesthesia.

    Science.gov (United States)

    Johnson, Addie; Jepma, Marieke; de Jong, Ritske

    2007-10-01

    Three experiments were conducted with 10 grapheme-colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme-colour synaesthesia may be bidirectional in the sense that not only do graphemes induce colours, but that colours influence the processing of graphemes. Using attentional blink and Stroop paradigms with digit targets, we found that some synaesthetes did report "seeing" synaesthetic colours even when they were not able to report the inducing digit. Moreover, congruency effects (effects of matching the colour of digit presentation with the synaesthetic colour associated with that digit) suggested that grapheme-colour synaesthesia can be bidirectional, at least for some synaesthetes.

  15. Colorimetry and prime colours--a theorem.

    Science.gov (United States)

    Hornaes, Hans Petter; Wold, Jan Henrik; Farup, Ivar

    2005-08-01

    Human colour vision is the result of a complex process involving topics ranging from physics of light to perception. Whereas the diversity of light entering the eye in principle span an infinite-dimensional vector space in terms of the spectral power distributions, the space of human colour perceptions is three dimensional. One important consequence of this is that a variety of colours can be visually matched by a mixture of only three adequately chosen reference lights. It has been observed that there exists one particular set of monochromatic reference lights that, according to a certain definition, is optimal for producing colour matches. These reference lights are commonly denoted prime colours. In the present paper, we intend to rigorously show that the existence of prime colours is not particular to the human visual system as sometimes stated, but rather an algebraic consequence of the manner in which a kind of colorimetric functions called colour-matching functions are defined and transformed. The solution is based on maximisation of a determinant determining the gamut size of the colour space spanned by the prime colours. Cramer's rule for solving a set of linear equations is an essential part of the proof. By means of examples, it is shown that mathematically the optimal set of reference lights is not unique in general, and that the existence of a maximum determinant is not a necessary condition for the existence of prime colours.

  16. Measurement and prediction of pork colour.

    Science.gov (United States)

    Van Oeckel, M J; Warnants, N; Boucqué, C V

    1999-08-01

    The extent to which instrumental colour determinations by FOPu (light scattering), Göfo (reflectance) and Labscan II (CIE L*, CIE a* and CIE b*, hue and chroma) are related to the Japanese colour grades was studied. Additionally, four on-line methods: pH1, FOP1, PQM1 (conductivity) and DDLT (Double Density Light Transmission, analogous to Capteur Gras/Maigre), were evaluated for their ability to predict subjectively and objectively colour. One hundred and twenty samples of m. longissimus thoracis et lumborum, from animals of different genotypes, were analysed. Of the instrumental colour determinations, CIE L* (r=-0.82), FOPu (r=-0.70) and Göfo (r=0.70) were best correlated with the Japanese colour scores. The Japanese colour grades could be predicted by the on-line instruments, pH1, FOP1, PQM1 and DDLT, with determination coefficients between 15 and 28%. Ultimate meat colour, determined by Japanese colour standards, FOPu, Göfo and CIE L*, was better predicted by DDLT than by the classic on-line instruments: FOP1, pH1 and PQM1, although the standard error of the estimate was similar for all instruments. This means that DDLT, although originally designed for estimating lean meat percentage, can additionally give information about meat quality, in particular colour. However, it must be stressed that the colour estimate by DDLT refers to a population of animals, rather than to individual pigs, because of the number of erroneously assigned samples.

  17. True and false memory for colour names versus actual colours: support for the visual distinctiveness heuristic in memory for colour information.

    Science.gov (United States)

    Eslick, Andrea N; Kostic, Bogdan; Cleary, Anne M

    2010-06-01

    In a colour variation of the Deese-Roediger-McDermott (DRM) false memory paradigm, participants studied lists of words critically related to a nonstudied colour name (e.g., "blood, cherry, scarlet, rouge ... "); they later showed false memory for the critical colour name (e.g., "red"). Two additional experiments suggest that participants generate colour imagery in response to such colour-related DRM lists. First, participants claim to experience colour imagery more often following colour-related than standard non-colour-related DRM lists; they also rate their colour imagery as more vivid following colour-related lists. Second, participants exhibit facilitative priming for critical colours in a dot selection task that follows words in the colour-related DRM list, suggesting that colour-related DRM lists prime participants for the actual critical colours themselves. Despite these findings, false memory for critical colour names does not extend to the actual colours themselves (font colours). Rather than leading to source confusion about which colours were self-generated and which were studied, presenting the study lists in varied font colours actually worked to reduce false memory overall. Results are interpreted within the framework of the visual distinctiveness hypothesis.

  18. Fruit over sunbed: carotenoid skin colouration is found more attractive than melanin colouration.

    Science.gov (United States)

    Lefevre, Carmen E; Perrett, David I

    2015-01-01

    Skin colouration appears to play a pivotal part in facial attractiveness. Skin yellowness contributes to an attractive appearance and is influenced both by dietary carotenoids and by melanin. While both increased carotenoid colouration and increased melanin colouration enhance apparent health in Caucasian faces by increasing skin yellowness, it remains unclear, firstly, whether both pigments contribute to attractiveness judgements, secondly, whether one pigment is clearly preferred over the other, and thirdly, whether these effects depend on the sex of the face. Here, in three studies, we examine these questions using controlled facial stimuli transformed to be either high or low in (a) carotenoid colouration, or (b) melanin colouration. We show, firstly, that both increased carotenoid colouration and increased melanin colouration are found attractive compared to lower levels of these pigments. Secondly, we show that carotenoid colouration is consistently preferred over melanin colouration when levels of colouration are matched. In addition, we find an effect of the sex of stimuli with stronger preferences for carotenoids over melanin in female compared to male faces, irrespective of the sex of the observer. These results are interpreted as reflecting preferences for sex-typical skin colouration: men have darker skin than women and high melanization in male faces may further enhance this masculine trait, thus carotenoid colouration is not less desirable, but melanin colouration is relatively more desirable in males compared to females. Taken together, our findings provide further support for a carotenoid-linked health-signalling system that is highly important in mate choice.

  19. Molecular tests for coat colours in horses.

    Science.gov (United States)

    Rieder, Stefan

    2009-12-01

    Colour phenotypes may have played a major role during early domestication events and initial selection among domestic animal species. As coat colours mostly follow a relatively simple mode of Mendelian inheritance, they have been among the first traits to be systematically analysed at the molecular level. As a result of the number of genetic tools developed during the past decade, horse coat colour tests have been designed and are now commercially available for some of the basic phenotypes. These tests enable breeders to verify segregation within particular pedigrees, to select specific colour phenotypes according to market demand or studbook policies and to avoid complex inherited diseases associated with some of the colour patterns. This paper reviews the relevance of the topic, describes all currently available tests for coat colours in horses and addresses also ongoing research in this field.

  20. Social perception in synaesthesia for colour.

    Science.gov (United States)

    Janik McErlean, Agnieszka B; Susilo, Tirta; Rezlescu, Constantin; Bray, Amy; Banissy, Michael J

    Synaesthesia is a rare phenomenon in which stimulation in one modality (e.g., audition) evokes a secondary percept not associated with the first (e.g., colour). Prior work has suggested links between synaesthesia and other neurodevelopmental conditions that are linked to altered social perception abilities. With this in mind, here we sought to examine social perception abilities in grapheme-colour synaesthesia (where achromatic graphemes evoke colour experiences) by examining facial identity and facial emotion perception in synaesthetes and controls. Our results indicate that individuals who experience grapheme-colour synaesthesia outperformed controls on tasks involving fine visual discrimination of facial identity and emotion, but not on tasks involving holistic face processing. These findings are discussed in the context of broader perceptual and cognitive traits previously associated with synaesthesia for colour, with the suggestion that performance benefits shown by grapheme-colour synaesthetes may be related to domain-general visual discrimination biases observed in this group.

  1. Colour-grapheme synaesthesia affects binocular vision

    Directory of Open Access Journals (Sweden)

    Chris L.E. Paffen

    2011-11-01

    Full Text Available In colour-grapheme synaesthesia, non-coloured graphemes are perceived as being inherently coloured. In recent years, it has become evident that synaesthesia-inducing graphemes can affect visual processing in a manner comparable to real, physical colours. Here, we exploit the phenomenon of binocular rivalry in which incompatible images presented dichoptically compete for conscious expression. Importantly, the competition only arises if the two images are sufficiently different; if the difference between the images is small, the images will fuse into a single mixed percept. We show that achromatic graphemes that induce synaesthetic colour percepts evoke binocular rivalry, while without the synaesthetic percept, they do not. That is, compared to achromatically perceived graphemes, synaesthesia-inducing graphemes increase the predominance of binocular rivalry over binocular fusion. This finding shows that the synaesthetic colour experience can provide the conditions for evoking binocular rivalry, much like stimulus features that induce rivalry in normal vision.

  2. Colour-independent partition functions in coloured vertex models

    CERN Document Server

    Foda, O

    2013-01-01

    We study lattice configurations related to S_n, the scalar product of an off-shell state and an on-shell state in rational A_n integrable vertex models, n = {1, 2}. The lattice lines are colourless and oriented. The state variables are n conserved colours that flow along the line orientations, but do not necessarily cover every bond in the lattice. Choosing boundary conditions such that the positions where the colours flow into the lattice are fixed, and where they flow out are summed over, we show that the partition functions of these configurations, with these boundary conditions, are n-independent. Our results extend to trigonometric A_n models, and to all n. This n-independence explains, in vertex-model terms, results from recent studies of S_2 [1, 2]. Namely, 1. S_2 which depends on two sets of Bethe roots, b_1 and b_2, and cannot (as far as we know) be expressed in single determinant form, degenerates in the limit b_1 -> infinity, and/or b_2 -> infinity, into a product of determinants, 2. Each of the la...

  3. Colour-independent partition functions in coloured vertex models

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O., E-mail: omar.foda@unimelb.edu.au [Dept. of Mathematics and Statistics, University of Melbourne, Parkville, VIC 3010 (Australia); Wheeler, M., E-mail: mwheeler@lpthe.jussieu.fr [Laboratoire de Physique Théorique et Hautes Energies, CNRS UMR 7589 (France); Université Pierre et Marie Curie – Paris 6, 4 place Jussieu, 75252 Paris cedex 05 (France)

    2013-06-11

    We study lattice configurations related to S{sub n}, the scalar product of an off-shell state and an on-shell state in rational A{sub n} integrable vertex models, n∈{1,2}. The lattice lines are colourless and oriented. The state variables are n conserved colours that flow along the line orientations, but do not necessarily cover every bond in the lattice. Choosing boundary conditions such that the positions where the colours flow into the lattice are fixed, and where they flow out are summed over, we show that the partition functions of these configurations, with these boundary conditions, are n-independent. Our results extend to trigonometric A{sub n} models, and to all n. This n-independence explains, in vertex-model terms, results from recent studies of S{sub 2} (Caetano and Vieira, 2012, [1], Wheeler, (arXiv:1204.2089), [2]). Namely, 1.S{sub 2}, which depends on two sets of Bethe roots, {b_1} and {b_2}, and cannot (as far as we know) be expressed in single determinant form, degenerates in the limit {b_1}→∞, and/or {b_2}→∞, into a product of determinants, 2. Each of the latter determinants is an A{sub 1} vertex-model partition function.

  4. Colour Vision Impairment in Young Alcohol Consumers.

    Directory of Open Access Journals (Sweden)

    Alódia Brasil

    Full Text Available Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test to test subject's ability to perform a colour arrangement task and the Mollon-Reffin test (MR test to measure subject's colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to

  5. Evolution of colour vision in mammals

    OpenAIRE

    Jacobs, Gerald H.

    2009-01-01

    Colour vision allows animals to reliably distinguish differences in the distributions of spectral energies reaching the eye. Although not universal, a capacity for colour vision is sufficiently widespread across the animal kingdom to provide prima facie evidence of its importance as a tool for analysing and interpreting the visual environment. The basic biological mechanisms on which vertebrate colour vision ultimately rests, the cone opsin genes and the photopigments they specify, are highly...

  6. Wood colour related to kiln drying

    OpenAIRE

    Sundqvist, Bror

    2000-01-01

    Raised temperature in artificial drying has led to some changes of wood products such as colour and strength etc. For special treatment of wood-products with clearly modified properties, among them colour, is often high temperature and steam used industrially. Knowledge about the colour rendering from wood that is subjected to heat under humid conditions and/or artificial drying, especially kiln drying, is thus of interest. It is also of interest to understand the chemical background, for the...

  7. Colour Vision Impairment in Young Alcohol Consumers

    Science.gov (United States)

    Brasil, Alódia; Castro, Antônio José O.; Martins, Isabelle Christine V. S.; Lacerda, Eliza Maria C. B.; Souza, Givago S.; Herculano, Anderson Manoel; Rosa, Alexandre Antônio M.; Rodrigues, Anderson R.; Silveira, Luiz Carlos L.

    2015-01-01

    Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test) to test subject’s ability to perform a colour arrangement task and the Mollon-Reffin test (MR test) to measure subject’s colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to neurotoxicants. PMID

  8. Colour Vision Impairment in Young Alcohol Consumers.

    Science.gov (United States)

    Brasil, Alódia; Castro, Antônio José O; Martins, Isabelle Christine V S; Lacerda, Eliza Maria C B; Souza, Givago S; Herculano, Anderson Manoel; Rosa, Alexandre Antônio M; Rodrigues, Anderson R; Silveira, Luiz Carlos L

    2015-01-01

    Alcohol consumption among young adults is widely accepted in modern society and may be the starting point for abusive use of alcohol at later stages of life. Chronic alcohol exposure can lead to visual function impairment. In the present study, we investigated the spatial luminance contrast sensitivity, colour arrangement ability, and colour discrimination thresholds on young adults that weekly consume alcoholic beverages without clinical concerns. Twenty-four young adults were evaluated by an ophthalmologist and performed three psychophysical tests to evaluate their vision functions. We estimated the spatial luminance contrast sensitivity function at 11 spatial frequencies ranging from 0.1 to 30 cycles/degree. No difference in contrast sensitivity was observed comparing alcohol consumers and control subjects. For the evaluation of colour vision, we used the Farnsworth-Munsell 100 hue test (FM 100 test) to test subject's ability to perform a colour arrangement task and the Mollon-Reffin test (MR test) to measure subject's colour discrimination thresholds. Alcohol consumers made more mistakes than controls in the FM100 test, and their mistakes were diffusely distributed in the FM colour space without any colour axis preference. Alcohol consumers also performed worse than controls in the MR test and had higher colour discrimination thresholds compared to controls around three different reference points of a perceptually homogeneous colour space, the CIE 1976 chromaticity diagram. There was no colour axis preference in the threshold elevation observed among alcoholic subjects. Young adult weekly alcohol consumers showed subclinical colour vision losses with preservation of spatial luminance contrast sensitivity. Adolescence and young adult age are periods of important neurological development and alcohol exposure during this period of life might be responsible for deficits in visual functions, especially colour vision that is very sensitive to neurotoxicants.

  9. Colour vision deficiency and physics teaching

    Science.gov (United States)

    Maule, Louise; Featonby, David

    2016-05-01

    1 in 12 males suffer from some form of colour vision deficiency (CVD) which in the present colour dominated world of education presentation can be a severe disadvantage. Although aware of ‘colourblindness’ most teachers make little or no adjustment for these pupils for whom tasks may be more difficult. This article examines colour vision deficiency and looks at ways in which we can help the many students who have this problem.

  10. Identification of Colour Reconnection using Factorial Correlator

    Institute of Scientific and Technical Information of China (English)

    FU Jing-Hua; LIU Lian-Shou

    2000-01-01

    A new signal is proposed for the colour reconnection in the hadronic decay of W+ W- in e+e- collisions. Using Pythia Monte Carlo it is shown that factorial correlators for W+ and W- without colour reconnection are almost identical to unity, while those for the cases with colour reconnection fall down approximately linearly in the log log plot. This signal, being based on the factorial correlator, is more sensitive than the ones using only averaged quantities.

  11. Colour in visualisation for computational fluid dynamics

    OpenAIRE

    2006-01-01

    Colour is used in computational fluid dynamic (CFD) simulations in two key ways. First it is used to visualise the geometry and allow the engineers to be confident that the model constructed is a good representation of the engineering situation. Once an analysis has been completed, colour is used in post-processing the data from the simulations to illustrate the complex fluid mechanic phenomena under investigation. This paper describes these two uses of colour and provides some examples to il...

  12. Hadronisation Models and Colour Reconnection

    CERN Document Server

    Bierlich, Christian

    2016-01-01

    Enhanced production of hadrons with $s$-quark content has been observed in $pp$ collisions at LHC, and earlier in collisions of heavy nuclei. We review the string hadronisation formalism and correc- tions from rope hadronisation and colour reconnection, corrections that takes place in such dense environments, and are able to correctly describe data. Since such corrections are very sensitive to the modelling of transverse proton structure, we investigate two such models, and compare to final states. Finally we describe how such corrections can also give a possible explanation to collective phenomena observed in small systems.

  13. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2011-01-01

    White Cast Iron (Ⅰ) White cast iron or ‘white iron' refers to the type of cast iron in which all of the carbon exists as carbide;there is no graphite in the as-cast structure and the fractured surface shows a white colour.White cast iron can be divided in three classes:· Normal white cast iron — this iron contains only C,Si,Mn,P and S,with no other alloying elements.· Low-alloy white cast iron — the total mass fraction of alloying elements is less than 5%.

  14. Colour assortative pairing in a colour polymorphic lizard is independent of population morph diversity

    Science.gov (United States)

    Pérez i de Lanuza, Guillem; Font, Enrique; Carretero, Miguel Ángel

    2016-10-01

    Previous work with a colour polymorphic population of Podarcis muralis (Lacertidae) revealed that lizards pair by ventral colour, favouring the same colour (i.e. homomorphic) pairs. Such assortative pairing, which probably results in colour assortative mating, can have consequences for the genetic structure of the population and potentially promote speciation. The population previously studied, located in the Pyrenees, encompasses white, yellow and orange animals, as well as intermediate white-orange and yellow-orange morphs. However, other Pyrenean populations of P. muralis have less ventral colour morphs. Our aim in this study is to test the generality of the assortative colour pairing system, extending our previous analyses to populations with different morph compositions and frequencies. The results show that the assortative pattern of pairing is similar in all the populations analysed and, hence, independent of morph composition and not restricted to pentamorphic populations. This suggests that assortative pairing by colour is a general phenomenon for colour polymorphic populations of P. muralis.

  15. Shell Colour Polymorphism in Bulla ampulla

    DEFF Research Database (Denmark)

    Cedhagen, Tomas

    1999-01-01

    Colour patterns of Bulla ampulla shells collected from Africa eastward to Pacific Islands were studied. 1\\vo common colour morphs were found. The typical morph is commonest. It is closely and finely mottled or all over with pinkish-gray on a creamy or flesh~tinted ground, with darker clouds......, irregular, V-shaped, or as longitudinal bands. The colouration of the other common morph is more uniform. It is lacking the darker clouds or bands and the colour is more greyish. The entire shell surface is densely mottled all over with small brown spots on a grey or beige background. Both morphs seem...

  16. Assessing the colour quality of LED sources

    DEFF Research Database (Denmark)

    Jost-Boissard, S.; Avouac, P.; Fontoynont, Marc

    2015-01-01

    sources and especially some LEDs. In this paper, several aspects of perceived colour quality are investigated using a side-by-side paired comparison method, and the following criteria: naturalness of fruits and vegetables, colourfulness of the Macbeth Color Checker chart, visual appreciation...... by the CIECAM02 Uniform Colour Space. Naturalness is better described by fidelity indices even if they did not give perfect predictions for all differences between LED light sources. Colourfulness is well described by gamut-based indices and attractiveness was found to correlate best with gamut-based indices...

  17. Clique colouring of binomial random graphs

    OpenAIRE

    Mcdiarmid, Colin; Mitsche, Dieter; Pralat, Pawel

    2016-01-01

    A clique colouring of a graph is a colouring of the vertices so that no maximal clique is monochromatic (ignoring isolated vertices). The smallest number of colours in such a colouring is the clique chromatic number. In this paper, we study the asymptotic behaviour of the clique chromatic number of the random graph G(n,p) for a wide range of edge-probabilities p=p(n). We see that the typical clique chromatic number, as a function of the average degree, forms an intriguing step function.

  18. Automated digital mapping of geological colour descriptions

    Science.gov (United States)

    Jenkins, Chris

    2002-12-01

    Sediment colour data are delivered by geologists as Munsell codes (Rock Color Chart) and linguistic descriptions. Using new software suitable for very large data sets, the two types can be brought into conformance and mapped together digitally. The native codes are extracted. For linguistic descriptions chromatic terms are identified with Munsell codes, then mixed in a temporary transform of psychometrically linear CIE colour space. Adjustments are made for dark/light and pale/strong modifiers. The output Munsell codes are statistically validated and mapped using special GIS legends to render them in true colour. The output displays provide a new view of marine sediment facies, comparable to remotely sensed colour imagery.

  19. An example of applied colour vision research: the conspicuity of airplane colour

    NARCIS (Netherlands)

    Lucassen, M.P.

    2002-01-01

    This paper describes the application of the combined knowledge on colorimetry, colour imaging (visualization) and colour perception in an aviation related research project. It involves the optimisation of the conspicuity of the colour scheme of an airplane, with the purpose of minimizing the changes

  20. Colours sometimes count : Awareness and bidirectionality in grapheme-colour synaesthesia

    NARCIS (Netherlands)

    Johnson, Addie; Jepma, Marieke; de Jong, Ritske

    2007-01-01

    Three experiments were conducted with 10 grapheme-colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme-colour synaesthesia may be bidirectional in the sense that not only do gr

  1. Colours sometimes count : Awareness and bidirectionality in grapheme-colour synaesthesia

    NARCIS (Netherlands)

    Johnson, Addie; Jepma, Marieke; de Jong, Ritske

    2007-01-01

    Three experiments were conducted with 10 grapheme-colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme-colour synaesthesia may be bidirectional in the sense that not only do gr

  2. An example of applied colour vision research: the conspicuity of airplane colour

    NARCIS (Netherlands)

    Lucassen, M.P.

    2002-01-01

    This paper describes the application of the combined knowledge on colorimetry, colour imaging (visualization) and colour perception in an aviation related research project. It involves the optimisation of the conspicuity of the colour scheme of an airplane, with the purpose of minimizing the changes

  3. Occupational colour vision requirements for police officers.

    Science.gov (United States)

    Birch, Jennifer; Chisholm, Catharine M

    2008-11-01

    Inclusion of public service professions in the UK Disability Discrimination Act in 2004 prompted a review of occupational colour vision requirements for police officers. Changes in the regulations which existed prior to 2003 were proposed. The aim of this study was to obtain the views of serving police officers in Northern Ireland on the importance of good colour discrimination in everyday police work and on the recruitment regulations for patrol constables introduced in 2003 in mainland UK. These views were obtained by means of a questionnaire and informal discussions. More than 65% of police officers who responded to the questionnaire considered that good colour vision was very important for effective policing. Fewer than 2% considered that colour vision was unimportant. Experienced police officers agreed that the employment of colour-deficient patrol constables, as permitted in the new regulations, would lead to reduced efficiency and organisational difficulties at the local level. A number of everyday activities were described which showed the need for accurate colour discrimination. The change in recruitment policy and the lack of clarity in the new regulations show inadequate appreciation of the needs of the occupation, of different types of colour vision anomalies and of the diagnostic function of colour vision tests. Failure to provide guidance on appropriate colour vision tests, examination procedures and counselling services is likely to result in inconsistent employment policies in different police forces. It is recommended that the colour vision standard in place prior to 2003 is reinstated at the recruitment stage. The Ishihara test should be used for screening, and colour-deficient applicants further examined with the Farnsworth D15 test as a replacement for the City University Test 2nd edition.

  4. Representing Object Colour in Language Comprehension

    Science.gov (United States)

    Connell, Louise

    2007-01-01

    Embodied theories of cognition hold that mentally representing something "red" engages the neural subsystems that respond to environmental perception of that colour. This paper examines whether implicit perceptual information on object colour is represented during sentence comprehension even though doing so does not necessarily facilitate task…

  5. Quantum theory of colour discrimination of dichromats

    NARCIS (Netherlands)

    Bouman, M.A.; Walraven, P.L.

    1962-01-01

    The hypothesis of de Vries and Rose has been applied to colour discrimination of dichromates. The hypothesis states that a brightness difference ΔB is just beyond threshold, when ΔB just exceeds the statistical fluctuations in background brightness B, which are proportional to B 1 2. The colour diff

  6. Brilliant Colours from a White Snow Cover

    Science.gov (United States)

    Vollmer, Michael; Shaw, Joseph A

    2013-01-01

    Surprisingly colourful views are possible from sparkling white snow. It is well known that similarly colourful features can exist in the sky whenever appropriate ice crystals are around. However, the transition of light reflection and refraction from ice crystals in the air to reflection and refraction from those in snow on the ground is not…

  7. Finite mutation classes of coloured quivers

    CERN Document Server

    Torkildsen, Hermund André

    2010-01-01

    We consider the general notion of coloured quiver mutation and show that the mutation class of a coloured quiver $Q$, arising from an $m$-cluster tilting object associated with $H$, is finite if and only if $H$ is of finite or tame representation type, or it has at most 2 simples. This generalizes a result known for 1-cluster categories.

  8. Colour measurement and white blood cell recognition

    CERN Document Server

    Gelsema, E S

    1972-01-01

    As a part of a collaboration with NEMCH aimed at the automation of the differential white blood cell count, studies have been made of the different possibilities for using colour to help in the recognition process. Results are presented comparing data obtained with a microspectrophotometer and with a simulated three-colour scanner.

  9. Instrumental colour classification of veal carcasses

    NARCIS (Netherlands)

    Hulsegge, B.; Engel, B.; Buist, W.; Merkus, G.S.M.; Klont, R.E.

    2001-01-01

    Three experiments, involving over 56 000 veal carcasses, were carried out to develop a method for instrumental colour classification of veal carcasses at 45 min post mortem with the Minolta CR300. The method should produce results similar to those of the 10-point colour-system, which is currently in

  10. Global skin colour prediction from DNA

    NARCIS (Netherlands)

    S. Walsh (Susan); L.C. Chaitanya (Lakshmi); Breslin, K. (Krystal); Muralidharan, C. (Charanya); Bronikowska, A. (Agnieszka); E. Pośpiech (Ewelina); Koller, J. (Julia); L. Kovatsi (Leda); A. Wollstein (Andreas); W. Branicki (Wojciech); F. Liu; M.H. Kayser (Manfred)

    2017-01-01

    textabstractHuman skin colour is highly heritable and externally visible with relevance in medical, forensic, and anthropological genetics. Although eye and hair colour can already be predicted with high accuracies from small sets of carefully selected DNA markers, knowledge about the genetic

  11. Colour Perception on Facial Expression towards Emotion

    Directory of Open Access Journals (Sweden)

    Rubita Sudirman

    2012-12-01

    Full Text Available This study is to investigate human perceptions on pairing of facial expressions of emotion with colours. A group of 27 subjects consisting mainly of younger and Malaysian had participated in this study. For each of the seven faces, which expresses the basic emotions neutral, happiness, surprise, anger, disgust, fear and sadness, a single colour is chosen from the eight basic colours for the match of best visual look to the face accordingly. The different emotions appear well characterized by a single colour. The approaches used in this experiment for analysis are psychology disciplines and colours engineering. These seven emotions are being matched by the subjects with their perceptions and feeling. Then, 12 male and 12 female data are randomly chosen from among the previous data to make a colour perception comparison between genders. The successes or failures in running of this test depend on the possibility of subjects to propose their every single colour for each expression. The result will translate into number and percentage as a guide for colours designers and psychology field.

  12. Improved colour matching technique for fused nighttime imagery with daytime colours

    Science.gov (United States)

    Hogervorst, Maarten A.; Toet, Alexander

    2016-10-01

    Previously, we presented a method for applying daytime colours to fused nighttime (e.g., intensified and LWIR) imagery (Toet and Hogervorst, Opt.Eng. 51(1), 2012). Our colour mapping not only imparts a natural daylight appearance to multiband nighttime images but also enhances the contrast and visibility of otherwise obscured details. As a result, this colourizing method leads to increased ease of interpretation, better discrimination and identification of materials, faster reaction times and ultimately improved situational awareness (Toet e.a., Opt.Eng.53(4), 2014). A crucial step in this colouring process is the choice of a suitable colour mapping scheme. When daytime colour images and multiband sensor images of the same scene are available the colour mapping can be derived from matching image samples (i.e., by relating colour values to sensor signal intensities). When no exact matching reference images are available the colour transformation can be derived from the first-order statistical properties of the reference image and the multiband sensor image (Toet, Info. Fus. 4(3), 2003). In the current study we investigated new colour fusion schemes that combine the advantages of the both methods, using the correspondence between multiband sensor values and daytime colours (1st method) in a smooth transformation (2nd method). We designed and evaluated three new fusion schemes that focus on: i) a closer match with the daytime luminances, ii) improved saliency of hot targets and iii) improved discriminability of materials

  13. Material and lighting dimensions of object colour.

    Science.gov (United States)

    Tokunaga, Rumi; Logvinenko, Alexander D

    2010-08-06

    The dimensionality of the object colour manifold was studied using a multidimensional scaling technique, which allows for the representation of a set of coloured papers as a configuration in a Euclidean space where the distance between papers corresponds to the perceptual dissimilarities between them. When the papers are evenly illuminated they can be arranged as a three-dimensional configuration. This is in line with the generally accepted view that the object colour space is three-dimensional. Yet, we show that under variegated illumination another three dimensions emerge. We call them lighting dimensions of object colour in order to distinguish from the traditional three referred to as material dimensions of object colour. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Colour-grapheme synesthesia affects binocular vision.

    Science.gov (United States)

    Paffen, Chris L E; van der Smagt, Maarten J; Nijboer, Tanja C W

    2011-01-01

    In colour-grapheme synesthesia, non-coloured graphemes are perceived as being inherently coloured. In recent years, it is debated whether visual processing of synesthesia-inducing achromatic graphemes is similar to that of chromatic graphemes. Here, we exploit the phenomenon of binocular rivalry in which incompatible images presented dichoptically compete for conscious expression. Importantly, the competition only arises if the two images are sufficiently different; if the difference between the images is small, the images will fuse into a single mixed percept. We show that achromatic digits that induce synesthetic colour percepts increase the incidence of binocular rivalry compared to achromatic non-digits that do not evoke such percepts. That is, compared to achromatically perceived non-digits, synesthesia-inducing digits increase the predominance of binocular rivalry over binocular fusion. This finding shows that the synesthetic colour experience can provide the conditions for promoting binocular rivalry, much like stimulus features that induce rivalry in normal vision.

  15. The colour of pain: can patients use colour to describe osteoarthritis pain?

    Science.gov (United States)

    Wylde, Vikki; Wells, Victoria; Dixon, Samantha; Gooberman-Hill, Rachael

    2014-03-01

    The aim of the present study was to explore patients' views on the acceptability and feasibility of using colour to describe osteoarthritis (OA) pain, and whether colour could be used to communicate pain to healthcare professionals. Six group interviews were conducted with 17 patients with knee OA. Discussion topics included first impressions about using colour to describe pain, whether participants could associate their pain with colour, how colours related to changes to intensity and different pain qualities, and whether they could envisage using colour to describe pain to healthcare professionals. The group interviews indicated that, although the idea of using colour was generally acceptable, it did not suit all participants as a way of describing their pain. The majority of participants chose red to describe high-intensity pain; the reasons given were because red symbolized inflammation, fire, anger and the stop signal in a traffic light system. Colours used to describe the absence of pain were chosen because of their association with positive emotional feelings, such as purity, calmness and happiness. A range of colours was chosen to represent changes in pain intensity. Aching pain was consistently identified as being associated with colours such as grey or black, whereas sharp pain was described using a wider selection of colours. The majority of participants thought that they would be able to use colour to describe their pain to healthcare professionals, although issues around the interpretability and standardization of colour were raised. For some patients, using colour to describe their pain experience may be a useful tool to improve doctor-patient communication. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Accurate representation of interference colours (Michel-Lévy chart): from rendering to image colour correction.

    Science.gov (United States)

    Linge Johnsen, S A; Bollmann, J; Lee, H W; Zhou, Y

    2017-09-21

    Here a work flow towards an accurate representation of interference colours (Michel-Lévy chart) digitally captured on a polarised light microscope using dry and oil immersion objectives is presented. The work flow includes accurate rendering of interference colours considering the colour temperature of the light source of the microscope and chromatic adaptation to white points of RGB colour spaces as well as the colour correction of the camera using readily available colour targets. The quality of different colour correction profiles was tested independently on an IT8.7/1 target. The best performing profile was using the XYZ cLUT algorithm and it revealed a ΔE00 of 1.9 (6.4 no profile) at 5× and 1.1 (8.4 no profile) at 100× magnification, respectively. The overall performance of the workflow was tested by comparing rendered interference colours with colour-corrected images of a quartz wedge captured over a retardation range from 80-2500 nm at 5× magnification. Uncorrected images of the quartz wedge in sRGB colour space revealed a mean ΔE00 of 12.3, which could be reduced to a mean of 4.9 by applying a camera correction profile based on an IT8.7/1 target and the Matrix only algorithm (ΔE00 < 1.0 signifies colour differences imperceptible by the human eye). ΔE00 varied significantly over the retardation range of 80-2500 nm of the quartz wedge, but the reasons for this variation is not well understood and the quality of colour correction might be further improved in future by using custom made colour targets specifically designed for the analysis of high-order interference colours. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  17. Most and Least Preferred Colours Differ According to Object Context: New Insights from an Unrestricted Colour Range.

    Directory of Open Access Journals (Sweden)

    Domicele Jonauskaite

    Full Text Available Humans like some colours and dislike others, but which particular colours and why remains to be understood. Empirical studies on colour preferences generally targeted most preferred colours, but rarely least preferred (disliked colours. In addition, findings are often based on general colour preferences leaving open the question whether results generalise to specific objects. Here, 88 participants selected the colours they preferred most and least for three context conditions (general, interior walls, t-shirt using a high-precision colour picker. Participants also indicated whether they associated their colour choice to a valenced object or concept. The chosen colours varied widely between individuals and contexts and so did the reasons for their choices. Consistent patterns also emerged, as most preferred colours in general were more chromatic, while for walls they were lighter and for t-shirts they were darker and less chromatic compared to least preferred colours. This meant that general colour preferences could not explain object specific colour preferences. Measures of the selection process further revealed that, compared to most preferred colours, least preferred colours were chosen more quickly and were less often linked to valenced objects or concepts. The high intra- and inter-individual variability in this and previous reports furthers our understanding that colour preferences are determined by subjective experiences and that most and least preferred colours are not processed equally.

  18. Physicochemical and physiological basis of dichromatic colour

    Science.gov (United States)

    Kreft, Samo; Kreft, Marko

    2007-11-01

    Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum.

  19. Colour and lighting in hospital design

    Science.gov (United States)

    Dalke, Hilary; Little, Jenny; Niemann, Elga; Camgoz, Nilgun; Steadman, Guillaume; Hill, Sarah; Stott, Laura

    2006-06-01

    Little information or guidance has been available to assist the development of a hospital's visual environment. A report on lighting and colour design schemes, accessible to non professionals with responsibility for refurbishment strategies, was required by NHS Estates. Firstly, 20 hospitals were audited to establish a picture of current practice and to identify key issues where colour design could broadly enhance the environment for patients, staff and visitors. Critical areas were outlined in this report, where colour design can be utilised and applied, for the benefit of all users, from ambience to essential legal requirements such as colour contrast for the visually impaired. Provision of staff relaxation rooms that are different in terms of colour and lux levels from immediate work spaces, or thoughtfully designed areas for patients awaiting intensive treatment, have been shown to have some beneficial effects on a sense of well being. Colour and design have not been established as a definite cure for sickness and ill health, but certainly monotony and poor conditions in premises that have not been refurbished with any care, have had a detrimental affect on recovery rates and staff morale. The realisation that a well balanced and attractive environment is of major importance to patients' health is, in no way new; Florence Nightingale observed that 'a variety of form and brilliance of colour in the objects presented to patients are an actual means of recovery'.

  20. Kansei Colour Concepts to Improve Effective Colour Selection in Designing Human Computer Interfaces

    Directory of Open Access Journals (Sweden)

    Tharangie K G D

    2010-05-01

    Full Text Available Colours have a major impact on Human Computer Interaction. Although there is a very thin line between appropriate and inappropriate use of colours, if used properly, colours can be a powerful tool to improve the usefulness of a computer interface in a wide variety of areas. Many designers mostly consider the physical aspect of the colour and tend to forget that psychological aspect of colour exists. However the findings of this study confirm that the psychological aspect or the affective dimension of colour also plays an important role in colour Interface design towards user satisfaction. Using Kansei Engineering principles the study explores the affective variability of colours and how it can be manipulated to provide better design guidance and solutions. A group of twenty adults from Sri Lanka, age ranging from 30 to 40 took part in the study. Survey was conducted using a Kansei colour questionnaire in normal atmospheric conditions. The results reveal that the affective variability of colours plays an important role in human computer interaction as an influential factor in drawing the user towards or withdrawing from the Interface. Thereby improving or degrading the user satisfaction.

  1. Using students' misconceptions of primary coloured lights to design a hands-on coloured light mixer

    Science.gov (United States)

    Nopparatjamjomras, Suchai; Chitaree, Ratchapak

    2009-06-01

    A surface mount typed multi-coloured Light-Emitting Diode (LED) is used as a light source for the hands-on coloured light mixer. The LED consists of red, green and blue tiny sources but the mixer is designed to have four switches corresponding to red, green, blue and yellow light. These colours correspond to students' misconceptions of primary coloured lights; they realize that the primary colours and the rules for lights mixing are the same as those of paints. To generate a yellow light, a microcontroller placed between four input switches and the LED operates both a red and green tiny sources. In addition, the microcontroller is employed to eliminate some combinations of coloured light mixing to simplify the experiment (basic mode) for non advanced students. If the mixer is used with more advanced students, a number of combinations will increase and students need more analytical skills to find out the primary coloured lights (the coloured lights that can not be produced by the mixing of any other coloured lights). Therefore, the mixer is able to use with more advanced and non advanced students depending on the program in the microcontroller and some modifications of the circuit. Furthermore, to introduce students an idea that other hues or shades can be generated by mixing of these three primary coloured lights of different intensities, a tuning circuit is integrated to vary an intensity of the green light source.

  2. The colour wheels of art, perception, science and physiology

    Science.gov (United States)

    Harkness, Nick

    2006-06-01

    Colour is not the domain of any one discipline be it art, philosophy, psychology or science. Each discipline has its own colour wheel and this presentation examines the origins and philosophies behind the colour circles of Art, Perception, Science and Physiology (after image) with reference to Aristotle, Robert Boyle, Leonardo da Vinci, Goethe, Ewald Hering and Albert Munsell. The paper analyses and discusses the differences between the four colour wheels using the Natural Colour System® notation as the reference for hue (the position of colours within each of the colour wheels). Examination of the colour wheels shows the dominance of blue in the wheels of art, science and physiology particularly at the expense of green. This paper does not consider the three-dimensionality of colour space its goal was to review the hue of a colour with regard to its position on the respective colour wheels.

  3. Individual colour patches as multicomponent signals.

    Science.gov (United States)

    Grether, Gregory F; Kolluru, Gita R; Nersissian, Karen

    2004-08-01

    Colour patches are complex traits, the components of which may evolve independently through a variety of mechanisms. Although usually treated as simple, two-dimensional characters and classified as either structural or pigmentary, in reality colour patches are complicated, three-dimensional structures that often contain multiple pigment types and structural features. The basic dermal chromatophore unit of fishes, reptiles and amphibians consists of three contiguous cell layers. Xanthophores and erythrophores in the outermost layer contain carotenoid and pteridine pigments that absorb short-wave light; iridophores in the middle layer contain crystalline platelets that reflect light back through the xanthophores; and melanophores in the basal layer contain melanins that absorb light across the spectrum. Changes in any one component of a chromatophore unit can drastically alter the reflectance spectrum produced, and for any given adaptive outcome (e.g. an increase in visibility), there may be multiple biochemical or cellular routes that evolution could take, allowing for divergent responses by different populations or species to similar selection regimes. All of the mechanisms of signal evolution that previously have been applied to single ornaments (including whole colour patches) could potentially be applied to the individual components of colour patches. To reach a complete understanding of colour patch evolution, however, it may be necessary to take an explicitly multi-trait approach. Here, we review multiple trait evolution theory and the basic mechanisms of colour production in fishes, reptiles and amphibians, and use a combination of computer simulations and empirical examples to show how multiple trait evolution theory can be applied to the components of single colour patches. This integrative perspective on animal colouration opens up a host of new questions and hypotheses. We offer specific, testable functional hypotheses for the most common pigmentary

  4. Natural ingredients for colouring and styling.

    Science.gov (United States)

    Dweck, A C

    2002-10-01

    This paper examines some of the existing methods for colouring the hair and skin using natural material (such as henna) and proposes a parallel technology that exists in the dyeing of wool and fabrics to extend the colour range. Many of the listed plants and their derivatives are not found in Annex IV of the Cosmetic Directive and may not be used as colours; however, they do have other properties which may justify their inclusion into a product, for example, as astringent or anti-inflammatory agents. The paper concludes with some reported antigreying and hair styling preparations cited in the literature.

  5. Colour in visualisation for computational fluid dynamics

    Science.gov (United States)

    Kinnear, David; Atherton, Mark; Collins, Michael; Dokhan, Jason; Karayiannis, Tassos

    2006-06-01

    Colour is used in computational fluid dynamic (CFD) simulations in two key ways. First it is used to visualise the geometry and allow the engineer to be confident that the model constructed is a good representation of the engineering situation. Once an analysis has been completed, colour is used in post-processing the data from the simulations to illustrate the complex fluid mechanic phenomena under investigation. This paper describes these two uses of colour and provides some examples to illustrate the key visualisation approaches used in CFD.

  6. Internet Adaptation for Colour-Blind Persons

    Directory of Open Access Journals (Sweden)

    Rytė Žiūrienė

    2011-04-01

    Full Text Available Of all human race about 8% of males and 0,5% of females are colour-blind. It is estimated that in 2011 or 2012 there will be around 2 billion Internet users worldwide, so the number of colour-blind Internet users can reach about 200 million. Authors of this publication analyse issues that arise for colour-blind persons on the Internet and deliver the ways to make the Internet more comfortable. The special software is proposed as one of the ways together with comparison of its advantages.

  7. Galaxy And Mass Assembly (GAMA): Galaxy colour gradients versus colour, structure and luminosity

    CERN Document Server

    Kennedy, Rebecca; Häußler, Boris; Brough, Sarah; Holwerda, Benne; Hopkins, Andrew M; Vika, Marina; Vulcani, Benedetta

    2016-01-01

    Using single-component fits to SDSS/UKIDSS images of galaxies in the G09 region of the GAMA survey we study radial colour gradients across the galaxy population. We use the multiwavelength information provided by MegaMorph analysis of galaxy light profiles to calculate intrinsic colour gradients, and divide into six subsamples split by overall S\\'{e}rsic index ($n$) and galaxy colour. We find a bimodality in the colour gradients of high- and low-$n$ galaxies in all wavebands, which varies with overall galaxy luminosity. Global trends in colour gradients therefore result from combining the contrasting behaviour of a number of different galaxy populations. The ubiquity of strong negative colour gradients supports the picture of inside-out growth through gas accretion for blue, low-$n$ galaxies, and through dry minor mergers for red, high-$n$ galaxies. An exception is the blue high-n population, with properties indicative of dissipative major mergers.

  8. Why colour in subterranean vertebrates? Exploring the evolution of colour patterns in caecilian amphibians.

    Science.gov (United States)

    Wollenberg, K C; Measey, C John

    2009-05-01

    The proximate functions of animal skin colour are difficult to assign as they can result from natural selection, sexual selection or neutral evolution under genetic drift. Most often colour patterns are thought to signal visual stimuli; so,their presence in subterranean taxa is perplexing. We evaluate the adaptive nature of colour patterns in nearly a third of all known species of caecilians, an order of amphibians most of which live in tropical soils and leaf litter. We found that certain colour pattern elements in caecilians can be explained based on characteristics concerning above-ground movement. Our study implies that certain caecilian colour patterns have convergently evolved under selection and we hypothesize their function most likely to be a synergy of aposematism and crypsis, related to periods when individuals move overground. In a wider context, our results suggest that very little exposure to daylight is required to evolve and maintain a varied array of colour patterns in animal skin.

  9. STEGANALYSIS USING COLOUR MODEL CONVERSION

    Directory of Open Access Journals (Sweden)

    P.Thiyagarajan

    2012-01-01

    Full Text Available The major threat in cyber crime for digital forensic examiner is to identify, analyze and interpret theconcealed information inside digital medium such as image, audio and video. There are strong indicationsthat hiding information inside digital medium has been used for planning criminal activities. In this way, itis important to develop a steganalysis technique which detects the existence of hidden messages insidedigital medium. This paper focuses on universal image steganalysis method which uses RGB to HSI colourmodel conversion. Any Universal Steganalysis algorithm developed should be tested with various stegoimagesto prove its efficiency. The developed Universal Steganalysis algorithm is tested in stego-imagedatabase which is obtained by implementing various RGB Least Significant Bit Steganographic algorithms.Though there are many stego-image sources available on the internet it lacks in the information such ashow many rows has been infected by the steganography algorithms, how many bits have been modified andwhich channel has been affected. These parameters are important for Steganalysis algorithms and it helpsto rate its efficiency. Proposed Steganalysis using Colour Model has been tested with our Image Databaseand the results were affirmative.

  10. Steganalysis Using Colour Model Conversion

    Directory of Open Access Journals (Sweden)

    P.Thiyagarajan

    2011-12-01

    Full Text Available The major threat in cyber crime for digital forensic examiner is to identify, analyze and interpret theconcealed information inside digital medium such as image, audio and video. There are strong indicationsthat hiding information inside digital medium has been used for planning criminal activities. In this way, itis important to develop a steganalysis technique which detects the existence of hidden messages insidedigital medium. This paper focuses on universal image steganalysis method which uses RGB to HSI colourmodel conversion. Any Universal Steganalysis algorithm developed should be tested with various stegoimagesto prove its efficiency. The developed Universal Steganalysis algorithm is tested in stego-imagedatabase which is obtained by implementing various RGB Least Significant Bit Steganographic algorithms.Though there are many stego-image sources available on the internet it lacks in the information such ashow many rows has been infected by the steganography algorithms, how many bits have been modified andwhich channel has been affected. These parameters are important for Steganalysis algorithms and it helpsto rate its efficiency. Proposed Steganalysis using Colour Model has been tested with our Image Databaseand the results were affirmative.

  11. SATISFIABILITY METHODS FOR COLOURING GRAPHS

    Directory of Open Access Journals (Sweden)

    Munmun Dey

    2013-02-01

    Full Text Available The graph colouring problem can be solved using methods based on Satisfiability (SAT. An instance of the problem is defined by a Boolean expression written using Boolean variables and the logical connectives AND, OR and NOT. It has to be determined whether there is an assignment of TRUE and FALSE values to the variables that makes the entire expression true.A SAT problem is syntactically and semantically quite simple. Many Constraint Satisfaction Problems (CSPsin AI and OR can be formulated in SAT. These make use of two kinds of searchalgorithms: Deterministic and Randomized.It has been found that deterministic methods when run on hard CSP instances are frequently very slow in execution.A deterministic method always outputs a solution in the end, but it can take an enormous amount of time to do so.This has led to the development of randomized search algorithms like GSAT, which are typically based on local (i.e., neighbourhood search. Such methodshave been applied very successfully to find good solutions to hard decision problems

  12. Tetrachromacy, oil droplets and bird plumage colours.

    Science.gov (United States)

    Vorobyev, M; Osorio, D; Bennett, A T; Marshall, N J; Cuthill, I C

    1998-11-01

    There is a growing body of data on avian eyes, including measurements of visual pigment and oil droplet spectral absorption, and of receptor densities and their distributions across the retina. These data are sufficient to predict psychophysical colour discrimination thresholds for light-adapted eyes, and hence provide a basis for relating eye design to visual needs. We examine the advantages of coloured oil droplets, UV vision and tetrachromacy for discriminating a diverse set of avian plumage spectra under natural illumination. Discriminability is enhanced both by tetrachromacy and coloured oil droplets. Oil droplets may also improve colour constancy. Comparison of the performance of a pigeon's eye, where the shortest wavelength receptor peak is at 410 nm, with that of the passerine Leiothrix, where the ultraviolet-sensitive peak is at 365 nm, generally shows a small advantage to the latter, but this advantage depends critically on the noise level in the sensitivity mechanism and on the set of spectra being viewed.

  13. How to pass higher English colour

    CERN Document Server

    Bridges, Ann

    2009-01-01

    How to Pass is the Number 1 revision series for Scottish qualifications across the three examination levels of Standard Grade, Intermediate and Higher! Second editions of the books present all of the material in full colour for the first time.

  14. LED-Based Colour Sensing System

    Directory of Open Access Journals (Sweden)

    Ibrahim AL-BAHADLY

    2010-03-01

    Full Text Available This paper presents a new colour sensing system for measuring the colour of car paint accurately enough to reproduce the paint proportions to cover up scratches or wear on a car. The aim is to repaint a car’s damaged area at a fraction of the cost of repainting the whole car. The proposed colour sensing system is based on Light Emitting Diode (LED. A prototype for the system has been designed, built, and tested. During this work light was researched as well as lighting sources, how light travels, how light reflects and refracts, ways light can be quantized, the human eye, why cameras look accurate, lighting conditions and their effects, and the emergence of colour.

  15. Colour Management as a Precondition of Quality

    Directory of Open Access Journals (Sweden)

    Stefan Brues

    2004-12-01

    Full Text Available Colour management technology has reached a high level of maturity. Only ten years after it first appeared on the market, ICC colour profiles have become indispensable in modern premedia. It can be said without exaggeration that colour management has revolutionised digital proof printing. A whole range of newcomers in the print industry supplier community offer an intelligent combination of a PostScript RIP with integral colour management functions. The quality of these low-priced proofing systems has now reached such a high level that even discerning customers accept such digital proofs as contract proofs. Modular proofing solutions are regularly to be found among the leaders in the digital proofer tests.Working with colour profiles and profiled workflows is still a major problem area. It is no mere chance that notably digital proofing is the field in which users work with colour profiles in virtually all systems, since applications here are locally limited.An important step for the widespread use of colour management technology is the now very extensive implementation of ICC mechanisms in application programs such as Adobe Photoshop. Version 7 is regarded as a model of well thought-out ICC-based colour management implementation. As Microsoft has neglected the ICC standard in recent years, Adobe has created its own colour management interface, called ACE. Based on the ICC standard, it is regarded by many experts as a reference implementation. Adobe products, which are so important for the graphic arts industry, now contain a standard colour management platform across all supported operating systems. Incompatibilities at system level can now be virtually ruled out, at least across the Adobe product line, including the important interfaces with PostScript and PDF.Modern prepress technology is set to move ever further away from exclusive print production for standardised offset print. Multiple use of production data is still at an early stage

  16. Salience of Primary and Secondary Colours in Infancy

    Science.gov (United States)

    Franklin, Anna; Pitchford, Nicola; Hart, Lynsey; Davies, Ian R. L.; Clausse, Samantha; Jennings, Siobhan

    2008-01-01

    Primary colour terms ("black", "white", "red", "green", "yellow", and "blue") are more fundamental in colour language than secondary colour terms ("pink", "purple", "orange", "brown", and "grey"). Here, we assess whether this distinction exists in the absence of language, by investigating whether primary colours attract and sustain preverbal…

  17. Salience of Primary and Secondary Colours in Infancy

    Science.gov (United States)

    Franklin, Anna; Pitchford, Nicola; Hart, Lynsey; Davies, Ian R. L.; Clausse, Samantha; Jennings, Siobhan

    2008-01-01

    Primary colour terms ("black", "white", "red", "green", "yellow", and "blue") are more fundamental in colour language than secondary colour terms ("pink", "purple", "orange", "brown", and "grey"). Here, we assess whether this distinction exists in the absence of language, by investigating whether primary colours attract and sustain preverbal…

  18. Rockpool gobies change colour for camouflage.

    Directory of Open Access Journals (Sweden)

    Martin Stevens

    Full Text Available Camouflage is found in a wide range of species living in numerous habitat types, offering protection from visually guided predators. This includes many species from the intertidal zone, which must cope with background types diverse in appearance and with multiple predator groups foraging at high and low tide. Many animals are capable of either relatively slow (hours, days, weeks or rapid (seconds and minutes colour change in order to better resemble the background against which they are found, but most work has been restricted to a few species or taxa. It is often suggested that many small intertidal fish are capable of colour change for camouflage, yet little experimental work has addressed this. Here, we test rock gobies (Gobius paganellus for colour change abilities, and whether they can tune their appearance to match the background. In two experiments, we place gobies on backgrounds of different brightness (black or white, and of different colours (red and blue and use digital image analysis and modelling of predator (avian vision to quantify colour and luminance (perceived lightness changes and camouflage. We find that gobies are capable of rapid colour change (occurring within one minute, and that they can change their luminance on lighter or darker backgrounds. When presented on backgrounds of different colours, gobies also change their colour (hue and saturation while keeping luminance the same. These changes lead to predicted improvements in camouflage match to the background. Our study shows that small rockpool fish are capable of rapid visual change for concealment, and that this may be an important mechanism in many species to avoid predation, especially in complex heterogeneous environments.

  19. Plants and colour: Flowers and pollination

    Science.gov (United States)

    Miller, Renee; Owens, Simon J.; Rørslett, Bjørn

    2011-03-01

    While there is a range of colours found in plants the predominant colour is green. Pigments in plants have several roles e.g. photosynthesis and signalling. If colour is to be used as a signal then it must stand out from green. However, one should be aware that there are also coloured compounds where we have not yet fully investigated the role of colour in their functions—they may have roles in, for example, defence or heat exchange. In this paper, we will describe the basic chemistry of the major pigments found in plants and especially floral pigments. We will then discuss their locations in parts of the flower (such as sepals, petals, pollen and nectar), the cells in which they are found and their sub-cellular locations. Floral pigments have a large role to play in pollination of flowers by animals. They can and are modified in many ways during the development of flowers in nature, for example, at emergence and post-pollination. There are a range of biochemical mechanisms of colour change both within flowers and in isolated pigments. Some of the factors influencing colour are temperature, co-pigments, pH, metals, sugars, anthocyanin stacking and cell shape. There is a renewed interest in analysing floral pigments and how they are modified partly because of advances in recombinant DNA technologies, but also because of pollinators and their significance to biodiversity and for evolutionary studies. There is continued strong interest from the horticultural industry for the introduction of new colours e.g. the blue rose and for the exploitation of natural dyes. Funding in this area may impact future research in a potentially beneficial way but it must not deflect us from science-based conservation.

  20. Colour hard-copy from workstation screens

    Science.gov (United States)

    Clayton, C. A.

    It is possible to produce a colour print on the DEC LJ250 inkjet printer of either the entire screen or a portion of the screen from VAXstations, DECstations, SUN workstations and the IKON image display. This document describes how to achieve this with each of the above workstations. The IKONPAINT software which is used to produce colour hard-copy from the IKON screen on the inkjet printer is fully documented in SUN/71 and is not described here.

  1. THE COLOUR GLASS CONDENSATE: AN INTRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    IANCU,E.; LEONIDOV,A.; MCLERRAN,L.

    2001-08-06

    In these lectures, the authors develop the theory of the Colour Glass Condensate. This is the matter made of gluons in the high density environment characteristic of deep inelastic scattering or hadron-hadron collisions at very high energy. The lectures are self contained and comprehensive. They start with a phenomenological introduction, develop the theory of classical gluon fields appropriate for the Colour Glass, and end with a derivation and discussion of the renormalization group equations which determine this effective theory.

  2. Pulmonary echography in systemic sclerosis.

    Science.gov (United States)

    Moazedi-Fuerst, F C; Zechner, P M; Tripolt, N J; Kielhauser, S M; Brickmann, K; Scheidl, S; Lutfi, A; Graninger, W G

    2012-11-01

    In systemic sclerosis patients, interstitial lung disease and pulmonary hypertension are highly associated with mortality. The time point of detecting manifestations like pulmonary hypertension and interstitial lung disease (ILD) is of vital importance. High-resolution computed tomography (HRCT) to date is the gold standard to diagnose ILD. In addition, an ultrasound of the lung is suggested as a noninvasive and radiation-free method of structural monitoring of the lung. We tested the reliability of lung sonography for the assessment of patients with systemic sclerosis. In a pilot study involving 25 patients with systemic sclerosis and 40 healthy volunteers, we screened the pleura and the pulmonary parenchyma for sonographic abnormalities. The occurrence of B lines, comet tail phenomena, and pleural irregularities was scored. All systemic sclerosis (SSc) patients were subjected to computed x-ray tomography of the chest. Forty-four percent of SSc patients showed B line phenomena and pleural thickening. The diagnosis of ILD in these patients was confirmed by HRCT scan. B line phenomena and pleural irregularities were significantly more common in SSc patients. Patients with ILD had higher pleural scores and comet scores when compared to systemic sclerosis patients without radiographic ILD. If our results are confirmed in larger studies, transthoracic ultrasound of the lung might turn out to be a suitable method for screening patients with systemic sclerosis for incipient pulmonary structural changes.

  3. The Application of Happening Colour in Modern Fabric Design

    Institute of Scientific and Technical Information of China (English)

    PAN Chun-yu

    2006-01-01

    To expand the past and present colour concept and reinvent fabric design methods, happening colour is used as a kind of new colour concept and form to design and analyse the resource of colour. With the aid of sophisticated computer software and advanced digital printing machines, happening colour allows images of considerable complication and intricacy to be designed and produced in modern fabric design by various arrangement of printing colours, which also allows further shifts of colour emphasis of the different visual and psychogenic recept.

  4. Flower colour adaptation in a mimetic orchid.

    Science.gov (United States)

    Newman, Ethan; Anderson, Bruce; Johnson, Steven D

    2012-06-22

    Although the tremendous variability in floral colour among angiosperms is often attributed to divergent selection by pollinators, it is usually difficult to preclude the possibility that floral colour shifts were driven by non-pollinator processes. Here, we examine the adaptive significance of flower colour in Disa ferruginea, a non-rewarding orchid that is thought to attract its butterfly pollinator by mimicking the flowers of sympatric nectar-producing species. Disa ferruginea has red flowers in the western part of its range and orange flowers in the eastern part--a colour shift that we hypothesized to be the outcome of selection for resemblance to different local nectar-producing plants. Using reciprocal translocations of red and orange phenotypes as well as arrays of artificial flowers, we found that the butterfly Aeropetes tulbaghia, the only pollinator of the orchid, preferred both the red phenotype and red artificial flowers in the west where its main nectar plant also has red flowers, and both the orange phenotype and orange artificial flowers in the east, where its main nectar plant has orange flowers. This phenotype by environment interaction demonstrates that the flower colour shift in D. ferruginea is adaptive and driven by local colour preference in its pollinator.

  5. Laser-induced plasmonic colours on metals

    Science.gov (United States)

    Guay, Jean-Michel; Calà Lesina, Antonino; Côté, Guillaume; Charron, Martin; Poitras, Daniel; Ramunno, Lora; Berini, Pierre; Weck, Arnaud

    2017-07-01

    Plasmonic resonances in metallic nanoparticles have been used since antiquity to colour glasses. The use of metal nanostructures for surface colourization has attracted considerable interest following recent developments in plasmonics. However, current top-down colourization methods are not ideally suited to large-scale industrial applications. Here we use a bottom-up approach where picosecond laser pulses can produce a full palette of non-iridescent colours on silver, gold, copper and aluminium. We demonstrate the process on silver coins weighing up to 5 kg and bearing large topographic variations (~1.5 cm). We find that colours are related to a single parameter, the total accumulated fluence, making the process suitable for high-throughput industrial applications. Statistical image analyses of laser-irradiated surfaces reveal various nanoparticle size distributions. Large-scale finite-difference time-domain computations based on these nanoparticle distributions reproduce trends seen in reflectance measurements, and demonstrate the key role of plasmonic resonances in colour formation.

  6. Drug-induced hair colour changes.

    Science.gov (United States)

    Ricci, Francesco; De Simone, Clara; Del Regno, Laura; Peris, Ketty

    2016-12-01

    Hair colour modifications comprise lightening/greying, darkening, or even a complete hair colour change, which may involve the scalp and/or all body hair. Systemic medications may cause hair loss or hypertrichosis, while hair colour change is an uncommon adverse effect. The rapidly increasing use of new target therapies will make the observation of these side effects more frequent. A clear relationship between drug intake and hair colour modification may be difficult to demonstrate and the underlying mechanisms of hair changes are often unknown. To assess whether a side effect is determined by a specific drug, different algorithms or scores (e.g. Naranjo, Karch, Kramer, and Begaud) have been developed. The knowledge of previous similar reports on drug reactions is a key point of most algorithms, therefore all adverse events should be recognised and reported to the scientific community. Furthermore, even if hair colour change is not a life-threatening side effect, it is of deep concern for patient's quality of life and adherence to treatment. We performed a review of the literature on systemic drugs which may induce changes in hair colour.

  7. An Urban Colour Space in the Context of Culture

    Directory of Open Access Journals (Sweden)

    Olga Zheleznyak

    2015-08-01

    Full Text Available A colour space is seen as an actual discourse when discussing problems of formation and inhabitation of the modern city environment. The key aspect of such understanding is an activity-cultural interpretation of the urban environment colouristics proposed by the author, which allows building of an integral sphere of colour existence. This model of working with colour includes basic components and structures a colour space, while matching up all the elements (basic paradigms that provide proper functioning and development of the colour space; mechanisms of formation of colour paradigms; processes of formation and transformation of cultural norms and stereotypes; the culture of colour as a holistic unit that penetrates the variety of colour space forms, as well as the reality of colour establishment in the framework of human culture; the urban colouristics as a material and virtual, artificial and natural, organized and spontaneously appearing colour reality together with professional and conventional visions of it, etc..

  8. A Handheld LED Coloured-Light Mixer for Students to Learn Collaboratively the Primary Colours of Light

    Science.gov (United States)

    Nopparatjamjomras, Suchai; Chitaree, Ratchapak; Panijpan, Bhinyo

    2009-01-01

    To overcome students' inaccurate prior knowledge on primary additive colours, a coloured-light mixer has been constructed to enable students to observe directly the colours produced and reach the conclusion by themselves that the three primary colours of light are red, green, and blue (NOT red, yellow, and blue). Three closely packed tiny…

  9. The Attentional Capture of Colour in Visual Interface Design

    DEFF Research Database (Denmark)

    Andersen, Emil; Maier, Anja

    2017-01-01

    The use of colour is an integral component in visual interface design for creating separation between objects and for conveying meaning. It has previously been established that colours can be separated in a hierarchy of primary colours and secondary colours, and that colours are consistently...... at a sufficiently early level of processing to influence attention. We end by discussing implications of our results for design practice and research in psychology....

  10. Face colour under varying illumination - analysis and applications

    OpenAIRE

    Martinkauppi, B. (Birgitta)

    2002-01-01

    Abstract The colours of objects perceived by a colour camera are dependent on the illumination conditions. For example, when the prevailing illumination condition does not correspond to the one used in the white balancing of the camera, the object colours can change their appearance due to the lack of colour constancy capabilities. Many methods for colour constancy have been suggested but so far their performance has been inadequate. Faces are common and important objects encountered in ma...

  11. Seasonal Changes in Colour: A Comparison of Structural, Melanin- and Carotenoid-Based Plumage Colours

    Science.gov (United States)

    Delhey, Kaspar; Burger, Claudia; Fiedler, Wolfgang; Peters, Anne

    2010-01-01

    Background Plumage coloration is important for bird communication, most notably in sexual signalling. Colour is often considered a good quality indicator, and the expression of exaggerated colours may depend on individual condition during moult. After moult, plumage coloration has been deemed fixed due to the fact that feathers are dead structures. Still, many plumage colours change after moult, although whether this affects signalling has not been sufficiently assessed. Methodology/Principal Findings We studied changes in coloration after moult in four passerine birds (robin, Erithacus rubecula; blackbird, Turdus merula; blue tit, Cyanistes caeruleus; and great tit, Parus major) displaying various coloration types (melanin-, carotenoid-based and structural). Birds were caught regularly during three years to measure plumage reflectance. We used models of avian colour vision to derive two variables, one describing chromatic and the other achromatic variation over the year that can be compared in magnitude among different colour types. All studied plumage patches but one (yellow breast of the blue tit) showed significant chromatic changes over the year, although these were smaller than for a typical dynamic trait (bill colour). Overall, structural colours showed a reduction in relative reflectance at shorter wavelengths, carotenoid-based colours the opposite pattern, while no general pattern was found for melanin-based colours. Achromatic changes were also common, but there were no consistent patterns of change for the different types of colours. Conclusions/Significance Changes of plumage coloration independent of moult are probably widespread; they should be perceivable by birds and have the potential to affect colour signalling. PMID:20644723

  12. Flower colour and cytochromes P450.

    Science.gov (United States)

    Tanaka, Yoshikazu; Brugliera, Filippa

    2013-02-19

    Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3'-hydroxylase (F3'H) and flavonoid 3',5'-hydroxylase (F3'5'H) and thus they play a crucial role in the determination of flower colour. F3'H and F3'5'H mostly belong to CYP75B and CYP75A, respectively, except for the F3'5'Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3'5'H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3'5'H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3'5'H and F3'H in delphinidin-producing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones.

  13. Going global Management of colour-measuring instrumentation is the key to successful colour management

    Institute of Scientific and Technical Information of China (English)

    Peter Rachel.

    2007-01-01

    @@ It is no secret in the industry that even the best spectrophotometers exhibit colour drift with time. Software solutions are now available that can eliminate this drift and also use different manufacturers'drivers to calibrate literally all of the instruments involved in the colour process.

  14. Pollinators show flower colour preferences but flowers with similar colours do not attract similar pollinators.

    Science.gov (United States)

    Reverté, Sara; Retana, Javier; Gómez, José M; Bosch, Jordi

    2016-08-01

    Colour is one of the main floral traits used by pollinators to locate flowers. Although pollinators show innate colour preferences, the view that the colour of a flower may be considered an important predictor of its main pollinators is highly controversial because flower choice is highly context-dependent, and initial innate preferences may be overridden by subsequent associative learning. Our objective is to establish whether there is a relationship between flower colour and pollinator composition in natural communities. We measured the flower reflectance spectrum and pollinator composition in four plant communities (85 plant species represented by 109 populations, and 32 305 plant-pollinator interactions in total). Pollinators were divided into six taxonomic groups: bees, ants, wasps, coleopterans, dipterans and lepidopterans. We found consistent associations between pollinator groups and certain colours. These associations matched innate preferences experimentally established for several pollinators and predictions of the pollination syndrome theory. However, flowers with similar colours did not attract similar pollinator assemblages. The explanation for this paradoxical result is that most flower species are pollination generalists. We conclude that although pollinator colour preferences seem to condition plant-pollinator interactions, the selective force behind these preferences has not been strong enough to mediate the appearance and maintenance of tight colour-based plant-pollinator associations. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Genetic analyses of the human eye colours using a novel objective method for eye colour classification

    DEFF Research Database (Denmark)

    Andersen, Jeppe D.; Johansen, Peter; Harder, Stine

    2013-01-01

    In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically ...

  16. A simplified method for generation of pseudo natural colours from colour infrared aerial photos

    DEFF Research Database (Denmark)

    Knudsen, Thomas; Olsen, Brian Pilemann

    . In the second step the blue colour component is estimated using tailored models for each domain. Green and red colour components are taken directly fron the CIR photo. The visual impression of the results from the 2 step method is only slightly inferior to the original 7 step method. The implementation, however......In spite of their high potential for automated discrimination between vegetation and human made objects, colour-infrared (CIR) aerial photos have not been in widespread use for traditional photogrammetric mapping. This is probably due to their awkward colour representation invalidating the visual...... analytical experience of the stereo analysts doing the actual registration of the topographical data. In this paper, we present a method for generating pseudo natural colour (PNC) representations from CIR photos. This enables the combination of automated vegetation discrimination with traditional manual...

  17. Genetic analyses of the human eye colours using a novel objective method for eye colour classification

    DEFF Research Database (Denmark)

    Andersen, Jeppe D.; Johansen, Peter; Harder, Stine;

    2013-01-01

    In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically...... and TYR rs1393350) on the eye colour. We evaluated the two published prediction models for eye colour (IrisPlex [1] and Snipper[2]) and compared the predictions with the PIE-scores. We found good concordance with the prediction from individuals typed as HERC2 rs12913832 G. However, both methods had...... by different studies and to perform large meta-studies that may reveal loci with small effects on the eye colour....

  18. Sensory evaluation of meat colour using photographs

    Directory of Open Access Journals (Sweden)

    Gianluigi Destefanis

    2010-01-01

    Full Text Available Five m. longissimus thoracis steaks from different breeds, purchased at retail, were cut into samples and simultaneously photographed under standard shooting conditions. The first photo was taken on samples just arrived at the laboratory, the second one on a freshly cut surface after blooming. Two consumer panels evaluated beef colour using respectively photo 1 and photo 2. Each consumer was asked to rank samples in order of preference. Rank sums were evaluated with Fridman’s test. Immediately after taking the photos, colour was measured with a colorimeter. Regarding photo 1, consumers were able to discriminate one sample, the worst, from all the others. Concerning photo 2, consumers discriminated the worst sample, as in photo 1, but also the best one. Therefore a more accurate colour evaluation can be obtained if the assessment is carried out on a fresh cut surface after blooming. In general consumers preferred samples with high lightness and a relatively high yellowness. The sensory evaluation of meat colour using photographs is a promising tool to overcome the difficulties when the meat is directly evaluated. But it is very important to standardize the shooting conditions to obtain a true reproduction of the meat. For this purpose the use of a colour target is useful to check the validity of the adopted parameters.

  19. Improved colour to greyscale via integrability correction

    Science.gov (United States)

    Drew, Mark S.; Connah, David; Finlayson, Graham D.; Bloj, Marina

    2009-02-01

    The classical approach to converting colour to greyscale is to code the luminance signal as a grey value image. However, the problem with this approach is that the detail at equiluminant edges vanishes, and in the worst case the greyscale reproduction of an equiluminant image is a single uniform grey value. The solution to this problem, adopted by all algorithms in the field, is to try to code colour difference (or contrast) in the greyscale image. In this paper we reconsider the Socolinsky and Wolff algorithm for colour to greyscale conversion. This algorithm, which is the most mathematically elegant, often scores well in preference experiments but can introduce artefacts which spoil the appearance of the final image. These artefacts are intrinsic to the method and stem from the underlying approach which computes a greyscale image by a) calculating approximate luminance-type derivatives for the colour image and b) re-integrating these to obtain a greyscale image. Unfortunately, the sign of the derivative vector is sometimes unknown on an equiluminant edge and, in the current theory, is set arbitrarily. However, choosing the wrong sign can lead to unnatural contrast gradients (not apparent in the colour original). Our contribution is to show how this sign problem can be ameliorated using a generalised definition of luminance and a Markov relaxation.

  20. A four-colour optical detector circuit

    Science.gov (United States)

    Yohannes, Israel; Assaad, Maher

    2013-02-01

    In this article, a new architecture for a four-colour optical detector circuit is presented. The proposed detector uses a photodiode as its basic light transducing element and a mixed signal readout circuit for signal processing and decision making. The readout circuit requires only two comparators, two multiplexers and a few logic gates to produce a digital 4 bit output that represents the right colour detected. The proposed detector is advantageous because the number of required components is fixed even if the number of detected colours is increased. The feature of having a fixed number of elements while increasing the number of detected colours is important especially in component count (i.e. low cost) and low power consumption. The proposed detector can be used as an autonomous and portable real-time pH monitoring applications. The objective of this article is to present a validation of a novel four colour sensor architecture using simulation and experiment as a proof of concept for a future implementation as a CMOS integrated circuit using the Austria Microsystems 350 nm technology.

  1. Counting Coloured Planar Maps: Differential Equations

    Science.gov (United States)

    Bernardi, Olivier; Bousquet-Mélou, Mireille

    2017-08-01

    We address the enumeration of q-coloured planar maps counted by the number of edges and the number of monochromatic edges. We prove that the associated generating function is differentially algebraic, that is, satisfies a non-trivial polynomial differential equation with respect to the edge variable. We give explicitly a differential system that characterizes this series. We then prove a similar result for planar triangulations, thus generalizing a result of Tutte dealing with their proper q-colourings. In statistical physics terms, we solve the q-state Potts model on random planar lattices. This work follows a first paper by the same authors, where the generating function was proved to be algebraic for certain values of q, including {q=1, 2} and 3. It is known to be transcendental in general. In contrast, our differential system holds for an indeterminate q. For certain special cases of combinatorial interest (four colours; proper q-colourings; maps equipped with a spanning forest), we derive from this system, in the case of triangulations, an explicit differential equation of order 2 defining the generating function. For general planar maps, we also obtain a differential equation of order 3 for the four-colour case and for the self-dual Potts model.

  2. Coevolution of coloration and colour vision?

    Science.gov (United States)

    Lind, Olle; Henze, Miriam J; Kelber, Almut; Osorio, Daniel

    2017-07-05

    The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, and for the efficacy and honesty of biological communication. Here we outline current understanding of the diversity of colour vision in two contrasting groups: the phylogenetically conservative birds, and the more variable butterflies. Evidence for coevolution of colour signals and vision exists in both groups, but is limited to observations of phenotypic differences between visual systems, which might be correlated with coloration. Here, to illustrate how one might interpret the evolutionary significance of such differences, we used colour vision modelling based on an avian eye to evaluate the effects of variation in three key characters: photoreceptor spectral sensitivity, oil droplet pigmentation and the proportions of different photoreceptor types. The models predict that physiologically realistic changes in any one character will have little effect, but complementary shifts in all three can substantially affect discriminability of three types of natural spectra. These observations about the adaptive landscape of colour vision may help to explain the general conservatism of photoreceptor spectral sensitivities in birds. This approach can be extended to other types of eye and spectra to inform future work on coevolution of coloration and colour vision.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

  3. The effect of colour on children's cognitive performance.

    Science.gov (United States)

    Brooker, Alice; Franklin, Anna

    2016-06-01

    The presence of red appears to hamper adults' cognitive performance relative to other colours (see Elliot & Maier, 2014, Ann. Rev. Psychol. 65, 95). Here, we investigate whether colour affects cognitive performance in 8- and 9-year-olds. Children completed a battery of tasks once in the presence of a coloured screen that was one of eight colours and once in the presence of a grey screen. Performance was assessed for each colour relative to the grey baseline, and differences across colours were compared. We find a significant difference in performance across colours, with significantly worse performance in the presence of red than grey. The effect of colour did not significantly interact with task. The findings suggest that colour can affect children's cognitive performance and that there is a detrimental effect of red. Findings are related to the adult literature and implications for educational contexts are discussed. © 2015 The British Psychological Society.

  4. A comparison of colour micrographs obtained with a charged couple devise (CCD) camera and a 35-mm camera

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Smedegaard, Jesper; Jensen, Peter Koch

    2005-01-01

    ophthalmology, colour CCD camera, colour film, digital imaging, resolution, micrographs, histopathology, light microscopy......ophthalmology, colour CCD camera, colour film, digital imaging, resolution, micrographs, histopathology, light microscopy...

  5. Adaptive Marginal Median Filter for Colour Images

    Directory of Open Access Journals (Sweden)

    Almanzor Sapena

    2011-03-01

    Full Text Available This paper describes a new filter for impulse noise reduction in colour images which is aimed at improving the noise reduction capability of the classical vector median filter. The filter is inspired by the application of a vector marginal median filtering process over a selected group of pixels in each filtering window. This selection, which is based on the vector median, along with the application of the marginal median operation constitutes an adaptive process that leads to a more robust filter design. Also, the proposed method is able to process colour images without introducing colour artifacts. Experimental results show that the images filtered with the proposed method contain less noisy pixels than those obtained through the vector median filter.

  6. Are all the coloured galaxias the same?

    Science.gov (United States)

    Hidalgo-Gámez, A. M.; Miranda-Pérez, B. E.; Vega-Acevedo, I.; Castañeda, H.; Saviane, I.

    2016-06-01

    The coloured galaxies were recently discovered in the data-base of the SDSS. They are all compact and show unsual colours in the gri composite image. The most studied so far are those called "green peas" because of their green colour but there are bright blue, purple, red, orange, grey and pink. The green, purple and blue also share a large equivalent width in the oxygen forbbiden line [OIII]5007, larger than 200 Å, being more intense than Hα. This is quite unsual even for star forming galaxies. Although some authors have concluded that all three are the same kind of galaxies, we have studied them carefully and found out that there are important differences among the properties, including the scaling relations.

  7. A familial factor in the development of colour agnosia.

    Science.gov (United States)

    Nijboer, Tanja C W; van Zandvoort, Martine J E; de Haan, Edward H F

    2007-04-09

    An important aspect of research into the link between genes and behaviour concerns the identification of familial determination. There is evidence for familial factors in selective deficits, such as developmental dyslexia and developmental prosopagnosia. Colour agnosia concerns a selective neuropsychological condition in which colour perception is intact, while the identification and naming of colour is disrupted. We recently demonstrated that this deficit can occur as a developmental deficit. Here, we show that there is a familial factor in the development of colour agnosia by reporting the colour processing abilities of the mother and the daughters of a man with developmental colour agnosia.

  8. Multi-colour detection of gravitational arcs

    Science.gov (United States)

    Maturi, Matteo; Mizera, Sebastian; Seidel, Gregor

    2014-07-01

    Strong gravitational lensing provides fundamental insights into the understanding of the dark matter distribution in massive galaxies, galaxy clusters, and the background cosmology. Despite their importance, few gravitational arcs have been discovered so far. The urge for more complete, large samples and unbiased methods of selecting candidates increases. Several methods for the automatic detection of arcs have been proposed in the literature, but large amounts of spurious detections retrieved by these methods force observers to visually inspect thousands of candidates per square degree to clean the samples. This approach is largely subjective and requires a huge amount of checking by eye, especially considering the actual and upcoming wide-field surveys, which will cover thousands of square degrees. In this paper we study the statistical properties of the colours of gravitational arcs detected in the 37 deg2 of the CFHTLS-Archive-Research Survey (CARS). Most of them lie in a relatively small region of the (g' - r', r' - i') colour-colour diagram. To explain this property, we provide a model that includes the lensing optical depth expected in a ΛCDM cosmology that, in combination with the sources' redshift distribution of a given survey, in our case CARS, peaks for sources at redshift z ~ 1. By furthermore modelling the colours derived from the spectral energy distribution of the galaxies that dominate the population at that redshift, the model reproduces the observed colours well. By taking advantage of the colour selection suggested by both data and model, we automatically detected 24 objects out of 90 detected by eye checking. Compared with the single-band arcfinder, this multi-band filtering returns a sample complete to 83% and a contamination reduced by a factor of ~6.5. New gravitational arc candidates are also proposed.

  9. Colour-temperature correspondences: when reactions to thermal stimuli are influenced by colour.

    Science.gov (United States)

    Ho, Hsin-Ni; Van Doorn, George H; Kawabe, Takahiro; Watanabe, Junji; Spence, Charles

    2014-01-01

    In our daily lives, information concerning temperature is often provided by means of colour cues, with red typically being associated with warm/hot, and blue with cold. While such correspondences have been known about for many years, they have primarily been studied using subjective report measures. Here we examined this correspondence using two more objective response measures. First, we used the Implicit Association Test (IAT), a test designed to assess the strength of automatic associations between different concepts in a given individual. Second, we used a priming task that involved speeded target discrimination in order to assess whether priming colour or thermal information could invoke the crossmodal association. The results of the IAT confirmed that the association exists at the level of response selection, thus indicating that a participant's responses to colour or thermal stimuli are influenced by the colour-temperature correspondence. The results of the priming experiment revealed that priming a colour affected thermal discrimination reaction times (RTs), but thermal cues did not influence colour discrimination responses. These results may therefore provide important clues as to the level of processing at which such colour-temperature correspondences are represented.

  10. Duals of coloured quantum universal enveloping algebras and coloured universal $T$-matrices

    CERN Document Server

    Quesne, C

    1997-01-01

    We extend the notion of dually conjugate Hopf (super)algebras to the coloured Hopf (super)algebras ${\\cal H}^c$ that we recently introduced. We show that if the standard Hopf (super)algebras ${\\cal H}_q$ that are the building blocks of ${\\cal H}^c$ have Hopf duals ${\\cal H}_q^*$, then the latter may be used to construct coloured Hopf duals ${\\cal H}^{c*}$, endowed with coloured algebra and antipode maps, but with a standard coalgebraic structure. Next, we review the case where the ${\\cal H}_q$'s are quantum universal enveloping algebras of Lie (super)algebras $U_q(g)$, so that the corresponding ${\\cal H}_q^*$'s are quantum (super)groups $G_q$. We extend the Fronsdal and Galindo universal ${\\cal T}$-matrix formalism to the coloured pairs $(U^c(g), G^c)$ by defining coloured universal ${\\cal T}$-matrices. We then show that together with the coloured universal $\\cal R$-matrices previously introduced, the latter provide an algebraic formulation of the coloured RTT-relations, proposed by Basu-Mallick. This establi...

  11. Flower colour and cytochromes P450†

    OpenAIRE

    Tanaka, Yoshikazu; Brugliera, Filippa

    2013-01-01

    Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3′-hydroxylase (F3′H) and flavonoid 3′,5′-hydroxylase (F3′5′H) and thus they play a crucial role ...

  12. Colour and stellar population gradients in galaxies

    CERN Document Server

    Tortora, C; Cardone, V F; Capaccioli, M; Jetzer, P; Molinaro, R

    2010-01-01

    We discuss the colour, age and metallicity gradients in a wide sample of local SDSS early- and late-type galaxies. From the fitting of stellar population models we find that metallicity is the main driver of colour gradients and the age in the central regions is a dominant parameter which rules the scatter in both metallicity and age gradients. We find a consistency with independent observations and a set of simulations. From the comparison with simulations and theoretical considerations we are able to depict a general picture of a formation scenario.

  13. High-colour and mass hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Luest, D. (Muenchen Univ. (Germany, F.R.). Sektion Physik); Papantonopoulos, E.; Zoupanos, G. (European Organization for Nuclear Research, Geneva (Switzerland))

    1985-08-01

    We present a model based on the gauge group G=Gsub(HC).Gsub(S).SU(2)sub(L).U(1), where the hypercolour gauge group Gsub(HC) is responsible for the dynamical breaking of the strong group Gsub(S) to SU(3)sub(C) of QCD. Chiral symmetry breaking of high-colour representations produces dynamical breaking of the electroweak SU(2)sub(L).U(1) gauge group. Fermion masses and flavour mixing are dynamically generated from the condensations of high-colour representations. A phenomenological analysis of the model is also presented.

  14. Pitfalls in colour photography of choroidal tumours.

    Science.gov (United States)

    Schalenbourg, A; Zografos, L

    2013-02-01

    Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown.

  15. Colour and stellar population gradients in galaxies

    Science.gov (United States)

    Tortora, C.; Napolitano, N. R.; Cardone, V. F.; Capaccioli, M.; Jetzer, P.; Molinaro, R.

    We discuss the colour, age and metallicity gradients in a wide sample of local SDSS early- and late-type galaxies. From the fitting of stellar population models we find that metallicity is the main driver of colour gradients and the age in the central regions is a dominant parameter which rules the scatter in both metallicity and age gradients. We find a consistency with independent observations and a set of simulations. From the comparison with simulations and theoretical considerations we are able to depict a general picture of a formation scenario.

  16. Pitfalls in colour photography of choroidal tumours

    Science.gov (United States)

    Schalenbourg, A; Zografos, L

    2013-01-01

    Colour imaging of fundus tumours has been transformed by the development of digital and confocal scanning laser photography. These advances provide numerous benefits, such as panoramic images, increased contrast, non-contact wide-angle imaging, non-mydriatic photography, and simultaneous angiography. False tumour colour representation can, however, cause serious diagnostic errors. Large choroidal tumours can be totally invisible on angiography. Pseudogrowth can occur because of artefacts caused by different methods of fundus illumination, movement of reference blood vessels, and flattening of Bruch's membrane and sclera when tumour regression occurs. Awareness of these pitfalls should prevent the clinician from misdiagnosing tumours and wrongfully concluding that a tumour has grown. PMID:23238442

  17. Nonrepetitive Colourings of Planar Graphs with $O(\\log n)$ Colours

    CERN Document Server

    Dujmović, Vida; Joret, Gwenaël; Wood, David R

    2012-01-01

    A vertex colouring of a graph is \\emph{nonrepetitive} if there is no path for which the first half of the path is assigned the same sequence of colours as the second half. The \\emph{nonrepetitive chromatic number} of a graph $G$ is the minimum integer $k$ such that $G$ has a nonrepetitive $k$-colouring. Whether planar graphs have bounded nonrepetitive chromatic number is one of the most important open problems in the field. Despite this, the best known upper bound is $O(\\sqrt{n})$ for $n$-vertex planar graphs. We prove a $O(\\log n)$ upper bound.

  18. High Volume Colour Image Processing with Massively Parallel Embedded Processors

    NARCIS (Netherlands)

    Jacobs, Jan W.M.; Bond, W.; Pouls, R.; Smit, Gerard J.M.; Joubert, G.R.; Peters, F.J.; Tirado, P.; Nagel, W.E.; Plata, O.; Zapata, E.

    2006-01-01

    Currently Oce uses FPGA technology for implementing colour image processing for their high volume colour printers. Although FPGA technology provides enough performance it, however, has a rather tedious development process. This paper describes the research conducted on an alternative implementation

  19. Application of Modern Colour Measurement Dervices in Coloration Industries

    Institute of Scientific and Technical Information of China (English)

    CHUNG Y.S.; XIN John H.; SIN K.M.

    2002-01-01

    In colour measurement ralated industry, reflectance spectrophotometer is the one of the popular measuring machine for measutring colour and quality control. Colour communications is frequently confusing. This is because the colour appearance is subject to the influence of at least three different phenomena: the light source, the object and the visual system. The variation in either the radiant quantity or the spectral distribution of the source can alter the observed colour. Because of this reason,the objective quantitative tool, colour measurement equipment and communication method; become more important in evaluating of the colour. In fact, based on the advanced in computer system and electronic device,the colour measurement becomes more and more accuracy, especiany in spectrophotometer measurement.In this paper, we will focus on the review of modern spectrophotometers in coloration industries.

  20. Testing the AUDI2000 colour-difference formula for solid colours using some visual datasets with usefulness to automotive industry

    Science.gov (United States)

    Martínez-García, Juan; Melgosa, Manuel; Gómez-Robledo, Luis; Li, Changjun; Huang, Min; Liu, Haoxue; Cui, Guihua; Luo, M. Ronnier; Dauser, Thomas

    2013-11-01

    Colour-difference formulas are tools employed in colour industries for objective pass/fail decisions of manufactured products. These objective decisions are based on instrumental colour measurements which must reliably predict the subjective colour-difference evaluations performed by observers' panels. In a previous paper we have tested the performance of different colour-difference formulas using the datasets employed at the development of the last CIErecommended colour-difference formula CIEDE2000, and we found that the AUDI2000 colour-difference formula for solid (homogeneous) colours performed reasonably well, despite the colour pairs in these datasets were not similar to those typically employed in the automotive industry (CIE Publication x038:2013, 465-469). Here we have tested again AUDI2000 together with 11 advanced colour-difference formulas (CIELUV, CIELAB, CMC, BFD, CIE94, CIEDE2000, CAM02-UCS, CAM02-SCD, DIN99d, DIN99b, OSA-GP-Euclidean) for three visual datasets we may consider particularly useful to the automotive industry because of different reasons: 1) 828 metallic colour pairs used to develop the highly reliable RIT-DuPont dataset (Color Res. Appl. 35, 274-283, 2010); 2) printed samples conforming 893 colour pairs with threshold colour differences (J. Opt. Soc. Am. A 29, 883-891, 2012); 3) 150 colour pairs in a tolerance dataset proposed by AUDI. To measure the relative merits of the different tested colour-difference formulas, we employed the STRESS index (J. Opt. Soc. Am. A 24, 1823-1829, 2007), assuming a 95% confidence level. For datasets 1) and 2), AUDI2000 was in the group of the best colour-difference formulas with no significant differences with respect to CIE94, CIEDE2000, CAM02-UCS, DIN99b and DIN99d formulas. For dataset 3) AUDI2000 provided the best results, being statistically significantly better than all other tested colour-difference formulas.

  1. Central Limit Theorem for Coloured Hard Dimers

    Directory of Open Access Journals (Sweden)

    Maria Simonetta Bernabei

    2010-01-01

    Full Text Available We study the central limit theorem for a class of coloured graphs. This means that we investigate the limit behavior of certain random variables whose values are combinatorial parameters associated to these graphs. The techniques used at arriving this result comprise combinatorics, generating functions, and conditional expectations.

  2. Dissociation coloured quarks and inclusive scattering

    CERN Document Server

    Bartelski, J

    1974-01-01

    A simple parton model of the nucleon built up of three-triplet quarks dissociated into the Gell-Mann-Zweig quarks and 'coloured' gluons is considered. It is shown that the model is consistent with SLAC-MIT and CERN data for inclusive scattering. (21 refs).

  3. Recommended Colours for Use on Airborne Displays.

    Science.gov (United States)

    1982-11-01

    generation of military aircraft will also utilise such devices. There are a number of types of colour CRTs but the penetron and shadow mask devices are...towards 610 nm also typifies penetron displays. When these boundaries are superimposed on repre- sentative source (Fig 21) and surface (Fig 22) plots it

  4. A Brief Introduction to Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1997-01-01

    Coloured Petri Nets (CP-nets or CPN) is a graphical oriented language for design, specification, simulation and verification of systems. It is in particular well- suited for systems in which communication, synchronisation and resource sharing are important. Typical examples of application areas a...

  5. Structural Colour in Colourimetric Sensors and Indicators

    Science.gov (United States)

    2013-07-11

    Structural colour derives from enhanced scattering of particular spectral regions as opposed to absorption of light from a pigment . Light is scattered at...from different bacterial species35 and ageing conditions for different types of meat.107 We recently applied this combinatorial approach to our wetting

  6. Jottings on protective colour in animals

    NARCIS (Netherlands)

    Beaufort, de L.F.

    1964-01-01

    I have often been puzzled about the remarkable change of colour in the roedeer, a species that I can watch almost daily from my house. In the winter the greyish brown coat can hardly be distinguished against the dull, brownish shrubby wood, at the border of which they come to feed. The only visible

  7. Jottings on protective colour in animals

    NARCIS (Netherlands)

    Beaufort, de L.F.

    1964-01-01

    I have often been puzzled about the remarkable change of colour in the roedeer, a species that I can watch almost daily from my house. In the winter the greyish brown coat can hardly be distinguished against the dull, brownish shrubby wood, at the border of which they come to feed. The only visible

  8. Please pass me the skin coloured crayon!

    DEFF Research Database (Denmark)

    Zimmermann, Martina; Levisen, Carsten; Beck, Thorhalla Gudmundsdottir

    2015-01-01

    This study explores the cultural semantics of colour words in the four urban, European communities of Munich, Berne, Aarhus, and Reykjavik, focussing on hautfarben (German), hutfarb (Bernese Swiss German), hudfarvet (Danish), and húðlitur (Icelandic), all of which can be translated as ‘skin colou...

  9. Performance evaluation of local colour invariants

    NARCIS (Netherlands)

    Burghouts, G.J.; Geusebroek, J.M.

    2009-01-01

    In this paper, we compare local colour descriptors to grey-value descriptors. We adopt the evaluation framework of Mikolayzcyk and Schmid. We modify the framework in several ways. We decompose the evaluation framework to the level of local grey-value invariants on which common region descriptors are

  10. Size of colour singlets in QCD jets

    Science.gov (United States)

    Bertolini, S.; Marchesini, G.

    1982-11-01

    By using the jet calculus technique, the size of the colour singlet clusters of emitted partons of mass Q0 is estimated. For α(Q20)/πapplications of preconfinement in pertubbative QCD. This result is very sensitive to the correct treatment of infrared singularities. Permanent address: Istituto di Fisica, Università di Parma, Parma, Italy.

  11. Demonstration of the Colour Range of Indicators

    Science.gov (United States)

    Woods, G. T.

    1975-01-01

    Describes the construction of a box that is filled with indicator of a particular concentration. A little acid is added to one side and a little alkali to the other so that the complete colour range of the indicator is observable. (GS)

  12. Do quarks exist in four colours

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, M.; Aleem, F.E. (Punjab Univ., Lahore (Pakistan). Dept. of Physics)

    1981-12-19

    In this letter we show that recent experimental results on the ratio of sigma(e/sup +/e/sup -/..-->..hadrons) to sigma(e/sup +/e/sup -/..--> mu../sup +/..mu../sup -/) actually suggest a fourth colour for the quarks.

  13. Global skin colour prediction from DNA.

    Science.gov (United States)

    Walsh, Susan; Chaitanya, Lakshmi; Breslin, Krystal; Muralidharan, Charanya; Bronikowska, Agnieszka; Pospiech, Ewelina; Koller, Julia; Kovatsi, Leda; Wollstein, Andreas; Branicki, Wojciech; Liu, Fan; Kayser, Manfred

    2017-07-01

    Human skin colour is highly heritable and externally visible with relevance in medical, forensic, and anthropological genetics. Although eye and hair colour can already be predicted with high accuracies from small sets of carefully selected DNA markers, knowledge about the genetic predictability of skin colour is limited. Here, we investigate the skin colour predictive value of 77 single-nucleotide polymorphisms (SNPs) from 37 genetic loci previously associated with human pigmentation using 2025 individuals from 31 global populations. We identified a minimal set of 36 highly informative skin colour predictive SNPs and developed a statistical prediction model capable of skin colour prediction on a global scale. Average cross-validated prediction accuracies expressed as area under the receiver-operating characteristic curve (AUC) ± standard deviation were 0.97 ± 0.02 for Light, 0.83 ± 0.11 for Dark, and 0.96 ± 0.03 for Dark-Black. When using a 5-category, this resulted in 0.74 ± 0.05 for Very Pale, 0.72 ± 0.03 for Pale, 0.73 ± 0.03 for Intermediate, 0.87±0.1 for Dark, and 0.97 ± 0.03 for Dark-Black. A comparative analysis in 194 independent samples from 17 populations demonstrated that our model outperformed a previously proposed 10-SNP-classifier approach with AUCs rising from 0.79 to 0.82 for White, comparable at the intermediate level of 0.63 and 0.62, respectively, and a large increase from 0.64 to 0.92 for Black. Overall, this study demonstrates that the chosen DNA markers and prediction model, particularly the 5-category level; allow skin colour predictions within and between continental regions for the first time, which will serve as a valuable resource for future applications in forensic and anthropologic genetics.

  14. Displaying Photographic Images On Computer Monitors With Limited Colour Resolution

    Science.gov (United States)

    McFall, John D.; Mitchell, Joan L.; Pennebaker, William B.

    1989-04-01

    In this paper we address the problem of displaying continuous tone photographic colour images on CRT monitors on which only a limited number of colours can be displayed simultaneously. An algorithm is presented which generates a palette of a limited number of colours, and a method is given for the actual display of a full colour image using such a palette and its associated tables.

  15. Genetic analyses of the human eye colours using a novel objective method for eye colour classification

    DEFF Research Database (Denmark)

    Andersen, Jeppe D.; Johansen, Peter; Harder, Stine

    2013-01-01

    In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically......-score ranged from −1 to 1 (brown to blue). The software eliminated the need for user based interpretation and qualitative eye colour categories. In 94% (570) of 605 analyzed eye images, the iris region was successfully extracted and a PIE-score was calculated. A very high correlation between the PIE...... identified and extracted from high resolution digital images. DIAT was made user friendly with a graphical user interface. The software counted the number of blue and brown pixels in the iris image and calculated a Pixel Index of the Eye (PIE-score) that described the eye colour quantitatively. The PIE...

  16. The "Human Colour" Crayon: Investigating the Attitudes and Perceptions of Learners regarding Race and Skin Colour

    Directory of Open Access Journals (Sweden)

    Neeske Alexander

    2017-07-01

    Full Text Available Some coloured and black learners in South Africa use a light orange or pink crayon to represent themselves in art. Many learners name this colour “human colour” or “skin colour”. This is troublesome, because it could reflect exclusionary ways of representing race in images and language. This case study, conducted with two schools in the Western Cape, investigated Grade 3 learners’ attitudes and perceptions regarding race and skin colour through art processes and discussion. The aim was to promote critical engagement with race in Foundation Phase educational contexts. Suggestions include changing the language used to describe skin colour, just recognition and representation of races in educational resources and the promotion of critical citizenship education. This research indicates the need to create practical curriculum guidelines to discuss race issues in the South African classroom.

  17. Red, green, blue equals 1, 2, 3 : Investigating the bidirectionality of digit-colour synaesthesia

    NARCIS (Netherlands)

    Teichmann, A Lina; Nieuwenstein, Mark; Rich, Anina N

    In grapheme-colour synaesthesia, letters and digits elicit vivid and highly consistent experiences of colour. Typically, the conscious experience is unidirectional: digits elicit colours but colours do not elicit digits. If synaesthesia reflects an involuntary connection between representations,

  18. Colour picking: the pecking order of form and function

    NARCIS (Netherlands)

    Nack, F.-M.; Manniesing, A.S.K.; Hardman, L.

    2003-01-01

    Multimedia presentation generation has to be able to balance the functional aspects of a presentation that address the information needs of the user, and its aesthetic form. We demonstrate our approach using automatic colour design for which we integrate relevant aspects of colour theory. Colour sel

  19. Teaching the Absorption of Light Colours Using an Artificial Rainbow

    Science.gov (United States)

    Yurumezoglu, Kemal; Isik, Hakan; Arikan, Gizem; Kabay, Gozde

    2015-01-01

    This paper presents an experimental activity based on the absorption of light colours by pigments. The activity is constructed using a stepwise design and offers an opportunity for students and teachers to compare and generalize the interactions between light and pigment colours. The light colours composing an artificial rainbow produced in the…

  20. Summing large-N towers in colour flow evolution

    Energy Technology Data Exchange (ETDEWEB)

    Plaetzer, Simon

    2013-12-15

    We consider soft gluon evolution in the colour flow basis. We give explicit expressions for the colour structure of the (one-loop) soft anomalous dimension matrix for an arbitrary number of partons, and show how the successive exponentiation of classes of large-N contributions can be achieved to provide a systematic expansion of the evolution in terms of colour supressed contributions.

  1. Uniquely D-colourable digraphs with large girth

    CERN Document Server

    Harutyunyan, Ararat; Mohar, Bojan; Rafferty, Liam

    2011-01-01

    Let C and D be digraphs. A mapping $f:V(D)\\to V(C)$ is a C-colouring if for every arc $uv$ of D, either $f(u)f(v)$ is an arc of C or $f(u)=f(v)$, and the preimage of every vertex of C induces an acyclic subdigraph in D. We say that D is C-colourable if it admits a C-colouring and that D is uniquely C-colourable if it is surjectively C-colourable and any two C-colourings of D differ by an automorphism of C. We prove that if a digraph D is not C-colourable, then there exist digraphs of arbitrarily large girth that are D-colourable but not C-colourable. Moreover, for every digraph D that is uniquely D-colourable, there exists a uniquely D-colourable digraph of arbitrarily large girth. In particular, this implies that for every rational number $r\\geq 1$, there are uniquely circularly r-colourable digraphs with arbitrarily large girth.

  2. On the colour-colour properties of the Extremely Red Objects

    CERN Document Server

    Bergstrom, S; Bergstrom, Stefan; Wiklind, Tommy

    2004-01-01

    The colours of the galaxy class known as Extremely Red Objects (EROs; R-K>5) are considered to be consistent with two distinct galaxy populations at high redshift: evolved ellipticals or young dusty starbursts. In this paper the properties of EROs, spanned by the five photometric bands RIJHK, are investigated as to the possibility to distinguish between these two galaxy populations using only broad band photometry. The broad band colours of elliptical and starburst galaxies at redshifts up to 5 are computed from synthetic spectra obtained using the spectral evolution synthesis programme PEGASE.2. Two initial mass functions and a range of metallicities and extinctions are used. In order to be extremely red in the redshift range considered, the evolution of the R-K colour sets the requirement that ellipticals have to be less than 7-8 Gyr old, and that the starbursts must have colour excesses of E(B-V)>1, as derived from the nebular emission lines. In investigating the overlap in the different colour-colour plan...

  3. Counting with Colours? Effect of Colours on the Numerical Abilities of House Crows (Corvus splendens) and Common Myna (Acridotheres tristis)

    OpenAIRE

    Rahman, Nor Amira Abdul; Ali, Zalila; Zuharah, Wan Fatma; Nik FADZLY

    2016-01-01

    We conducted several aviary experiments to investigate the influence of colours in quantity judgments of two species of birds; house crow (Corvus splendens) and common myna (Acridotheres tristis). Different quantity (in seven different food proportions) of mealworms were presented nonsequentially to all birds using artificially coloured red mealworms, for experiment 1, and using artificially coloured green mealworms, for experiment 2. Both red and green coloured mealworms have no significant ...

  4. Colour correct: the interactive effects of food label nutrition colouring schemes and food category healthiness on health perceptions.

    Science.gov (United States)

    Nyilasy, Gergely; Lei, Jing; Nagpal, Anish; Tan, Joseph

    2016-08-01

    The purpose of the present study was to examine the effects of food label nutrition colouring schemes in interaction with food category healthiness on consumers' perceptions of food healthiness. Three streams of colour theory (colour attention, colour association and colour approach-avoidance) in interaction with heuristic processing theory provide consonant predictions and explanations for the underlying psychological processes. A 2 (food category healthiness: healthy v. unhealthy)×3 (food label nutrient colouring schemes: healthy=green, unhealthy=red (HGUR) v. healthy=red, unhealthy=green (HRUG) v. no colour (control)) between-subjects design was used. The research setting was a randomised-controlled experiment using varying formats of food packages and nutritional information colouring. Respondents (n 196) sourced from a national consumer panel, USA. The findings suggest that, for healthy foods, the nutritional colouring schemes reduced perceived healthiness, irrespective of which nutrients were coloured red or green (healthinesscontrol=4·86; healthinessHGUR=4·10; healthinessHRUG=3·70). In contrast, for unhealthy foods, there was no significant difference in perceptions of food healthiness when comparing different colouring schemes against the control. The results make an important qualification to the common belief that colour coding can enhance the correct interpretation of nutrition information and suggest that this incentive may not necessarily support healthier food choices in all situations.

  5. Interpreting the colour of an estuary

    Science.gov (United States)

    Bowers, D. G.; Evans, D.; Thomas, D. N.; Ellis, K.; Williams, P. J. le B.

    2004-01-01

    This paper explores the possibility of using water colour to quantify the concentration of coloured dissolved organic matter (CDOM), and through it, dissolved organic carbon (DOC) and salinity in a turbid estuary in which suspended sediments also influence water colour. The motivation of the work is that the method could be applied to water colour measurements made remotely from an aircraft (or, in larger estuaries, a satellite) enabling near-synoptic mapping of surface salinity and DOC distributions. The paper describes observations at 29 stations distributed along the salinity gradient of the Conwy estuary in North Wales. At each station, surface water samples were collected and analysed for salinity, concentrations of DOC, chlorophyll and suspended particles and absorption spectra of CDOM, or yellow substance. Profiles were made of both upwelling and downwelling irradiance in four narrow band channels, and these were used to calculate irradiance reflection and attenuation coefficients. Results show that spectrally averaged light absorption in the estuary is caused principally and equally by mineral suspended solids and yellow substance, with water and chlorophyll in third and fourth place. The CDOM is strongly correlated ( R2=0.99) in a negative sense with salinity, and more weakly correlated with DOC. There is a linear relationship between CDOM and the ratio of reflection coefficients in the red (670 nm) and blue-green (490 nm) parts of the spectrum, which could be applied to remote sensing; the slope and intercept of the relationship are however different to those found in less turbid water bodies. It is shown that the change in slope and intercept are consistent with the presence, in the Conwy estuary, of suspended particles which influence the water colour. A method is described and tested for inverting water colour measurements in a turbid estuary to give estimates of CDOM in the presence of suspended particles. The solution, which has not been adjusted to

  6. The Symbolism of Colour in the Modern German Youth Slang

    Directory of Open Access Journals (Sweden)

    Tetiana Shavlovska

    2016-08-01

    Full Text Available The article is devoted to the study of one of the most interesting for the research group of words – colour definitions – in the modern German youth slang. Different peoples created definite symbols of colours, still existing nowadays. Even at present time the problem of colour symbolism is one of the most significant while studying the interrelation between the colour and the psychic of a person. Youth is the most progressive, emotional and creative group of the society, that is why the study of such phenomenon as colour symbolism as the example of youth slang – is especially important for the modern linguocultural study and social linguistics.

  7. Colour Fading of Textile Fabric by Plasma Treatment

    Directory of Open Access Journals (Sweden)

    H. F. Cheung

    2013-01-01

    Full Text Available Colour fading of a reactive dye (C.I. Reactive Blue 19 dyed textile fabric was performed by atmospheric pressure plasma (APP treatment with the use of plasma jet. Under the APP treatment condition of treatment time = 5 sec/mm; ignition power = 160 W; oxygen concentration = 1%; jet distance = 3 mm, significant colour-fading effect was achieved. For comparison purpose, the reactive dye dyed textile fabric was subjected to conventional enzymatic colour-fading process. Experimental results revealed that the APP-induced colour-fading effect was comparable with conventional enzymatic colour-fading process.

  8. The Colour of the Young Universe

    Science.gov (United States)

    2003-12-01

    VLT study gives insight on the evolution of the star formation rate Summary An international team of astronomers [1] has determined the colour of the Universe when it was very young. While the Universe is now kind of beige, it was much bluer in the distant past , at a time when it was only 2,500 million years old. This is the outcome of an extensive and thorough analysis of more than 300 galaxies seen within a small southern sky area, the so-called Hubble Deep Field South. The main goal of this advanced study was to understand how the stellar content of the Universe was assembled and has changed over time. Dutch astronomer Marijn Franx , a team member from the Leiden Observatory (The Netherlands), explains: "The blue colour of the early Universe is caused by the predominantly blue light from young stars in the galaxies. The redder colour of the Universe today is caused by the relatively larger number of older, redder stars." The team leader, Gregory Rudnick from the Max-Planck Institut für Astrophysics (Garching, Germany) adds: "Since the total amount of light in the Universe in the past was about the same as today and a young blue star emits much more light than an old red star, there must have been significantly fewer stars in the young Universe than there is now. Our new findings imply that the majority of stars in the Universe were formed comparatively late, not so long before our Sun was born, at a moment when the Universe was around 7,000 million years old." These new results are based on unique data collected during more than 100 hours of observations with the ISAAC multi-mode instrument at ESO's Very Large Telescope (VLT), as part of a major research project, the Faint InfraRed Extragalactic Survey (FIRES) . The distances to the galaxies were estimated from their brightness in different optical near-infrared wavelength bands. PR Photo 34/03 : The Evolving Colour of the Universe . Observing the early Universe It is now well known that the Sun was formed

  9. Colour From the Perspective of Hadith: an Overview

    Directory of Open Access Journals (Sweden)

    Zainan Nazri Mohd Khairul Nizam

    2015-01-01

    Full Text Available Colour is mentioned a few times in the Prophetic Traditions, signifying its values and symbolic representation for the people. The Prophet PBUH highlighted the significance of certain colours by describing his preferred colours for his clothing and he also approved or discouraged the usage of certain colours. Among the colours that are specifically mentioned and found in the hadith are white, red, green, black and yellow. These colours give different connotations as they were used in the Prophet’s attires during battles and other occasions; and some bring about specific understanding, as stated by the Prophet PBUH. Interestingly, the use of certain colours as found in the hadith corresponds to that mentioned in the Qur’an. Thus, this paper will observe the discussion among Muhaddithin regarding to the topic of colours in terms of its definition, function, significance and impact on the human life. The variety of meaning and understanding of colours according to different perspectives and cultures will also be discussed. The implications of using specific colours psychologically and scientifically will also be exposed in order to discover the connection between colours in the Prophetic Traditions and in our contemporary life.

  10. Influence of Language on Colour Perception: A Simulationist Explanation

    Directory of Open Access Journals (Sweden)

    Loïc Paul Heurley

    2012-11-01

    Full Text Available “How can perception be altered by language?” is the fundamental question of this article. Indeed, various studies have pointed out the influence of colour-related knowledge on object and colour perception, evoked by linguistic stimuli. Here the relevance of the simulationist approach is assumed in order to explain this influence, where the understanding of colour-related words or sentences involves a process of colour simulation that is supported by a neuronal network partially similar to the network involved in colour perception. Consequently, colour-related knowledge and colour perception can interact through a process of pattern interference. In support of this idea, studies are discussed showing priming effects between colour simulation and colour perception, but two limitations are also raised. Firstly, these works all used between-category colour discrimination tasks that allow the intervention of lexical processes that can also explain priming. Secondly, these works control the congruency link between prime and target at the level of ‘colour category’, and no demonstration is made of an influence at the level of specific hues. Consequently, the simulationist view of language/perception interactions seems an interesting way to thinking but more experimens are needed in order to overcome some limitations.

  11. Uropygial gland and bib colouration in the house sparrow

    Directory of Open Access Journals (Sweden)

    Gregorio Moreno-Rueda

    2016-06-01

    Full Text Available Birds frequently signal different qualities by plumage colouration, mainly during mating. However, plumage colouration is determined during the moult, and therefore it would indicate the quality of individual birds during the moult, not its current quality. Recent studies, however, suggest that birds could modify plumage colouration by using cosmetic preen oil produced by the uropygial gland. In this study, I show that bib colouration is related to uropygial gland size and body condition in male house sparrows (Passer domesticus. Moreover, I conducted an experiment in which a group of sparrows were inoculated with an antigen, mimicking an illness. In control birds, short-term changes in bib colouration were related to both body condition and change in uropygial gland size. Therefore, birds that reduced uropygial gland size showed a greater colouration change. However, bib colouration did not change with the change in uropygial gland size in experimental birds inoculated with the antigen. Given that the experiment did not affect preen oil production or consumption, this finding tentatively suggests that the immune challenge provoked a change in the composition of preen oil, affecting its cosmetic properties. In short, the results of this study suggest that (1 male house sparrows produce cosmetic preen oil that alters the colouration of their bibs; (2 the more change in uropygial gland size, the more change in bib colouration; and (3 in this way, bib colouration has the potential to signal current health status, since less healthy birds showed less capacity to change bib colouration.

  12. Colour appearance descriptors for image browsing and retrieval

    Science.gov (United States)

    Othman, Aniza; Martinez, Kirk

    2008-01-01

    In this paper, we focus on the development of whole-scene colour appearance descriptors for classification to be used in browsing applications. The descriptors can classify a whole-scene image into various categories of semantically-based colour appearance. Colour appearance is an important feature and has been extensively used in image-analysis, retrieval and classification. By using pre-existing global CIELAB colour histograms, firstly, we try to develop metrics for whole-scene colour appearance: "colour strength", "high/low lightness" and "multicoloured". Secondly we propose methods using these metrics either alone or combined to classify whole-scene images into five categories of appearance: strong, pastel, dark, pale and multicoloured. Experiments show positive results and that the global colour histogram is actually useful and can be used for whole-scene colour appearance classification. We have also conducted a small-scale human evaluation test on whole-scene colour appearance. The results show, with suitable threshold settings, the proposed methods can describe the whole-scene colour appearance of images close to human classification. The descriptors were tested on thousands of images from various scenes: paintings, natural scenes, objects, photographs and documents. The colour appearance classifications are being integrated into an image browsing system which allows them to also be used to refine browsing.

  13. Uropygial gland and bib colouration in the house sparrow.

    Science.gov (United States)

    Moreno-Rueda, Gregorio

    2016-01-01

    Birds frequently signal different qualities by plumage colouration, mainly during mating. However, plumage colouration is determined during the moult, and therefore it would indicate the quality of individual birds during the moult, not its current quality. Recent studies, however, suggest that birds could modify plumage colouration by using cosmetic preen oil produced by the uropygial gland. In this study, I show that bib colouration is related to uropygial gland size and body condition in male house sparrows (Passer domesticus). Moreover, I conducted an experiment in which a group of sparrows were inoculated with an antigen, mimicking an illness. In control birds, short-term changes in bib colouration were related to both body condition and change in uropygial gland size. Therefore, birds that reduced uropygial gland size showed a greater colouration change. However, bib colouration did not change with the change in uropygial gland size in experimental birds inoculated with the antigen. Given that the experiment did not affect preen oil production or consumption, this finding tentatively suggests that the immune challenge provoked a change in the composition of preen oil, affecting its cosmetic properties. In short, the results of this study suggest that (1) male house sparrows produce cosmetic preen oil that alters the colouration of their bibs; (2) the more change in uropygial gland size, the more change in bib colouration; and (3) in this way, bib colouration has the potential to signal current health status, since less healthy birds showed less capacity to change bib colouration.

  14. Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls.

    Directory of Open Access Journals (Sweden)

    Tessa M van Leeuwen

    Full Text Available BACKGROUND: In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e.g., letters elicit colour. Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory integration. In several neuroimaging studies, enhanced brain activity for grapheme-colour synaesthesia has been found in ventral-occipital areas that are also involved in real colour processing. Our question was whether the neural correlates of synaesthetically induced colour and real colour experience are truly shared. METHODOLOGY/PRINCIPAL FINDINGS: First, in a free viewing functional magnetic resonance imaging (fMRI experiment, we located main effects of synaesthesia in left superior parietal lobule and in colour related areas. In the left superior parietal lobe, individual differences between synaesthetes (projector-associator distinction also influenced brain activity, confirming the importance of the left superior parietal lobe for synaesthesia. Next, we applied a repetition suppression paradigm in fMRI, in which a decrease in the BOLD (blood-oxygenated-level-dependent response is generally observed for repeated stimuli. We hypothesized that synaesthetically induced colours would lead to a reduction in BOLD response for subsequently presented real colours, if the neural correlates were overlapping. We did find BOLD suppression effects induced by synaesthesia, but not within the colour areas. CONCLUSIONS/SIGNIFICANCE: Because synaesthetically induced colours were not able to suppress BOLD effects for real colour, we conclude that the neural correlates of synaesthetic colour experience and real colour experience are not fully shared. We propose that synaesthetic colour experiences are mediated by higher-order visual pathways that lie beyond the scope of classical, ventral-occipital visual areas. Feedback from these areas, in which the left parietal

  15. Colour gradients in the optical and near-IR

    CERN Document Server

    De Jong, R S

    1995-01-01

    For many years broadband colours have been used to obtain insight into the contents of galaxies, in particular to estimate stellar and dust content. Broadband colours are easy to obtain for large samples of objects, making them ideal for statistical studies. In this paper I use the radial distribution of the colours in galaxies, which gives more insight into the local processes driving the global colour differences than integrated colours. Almost all galaxies in my sample of 86 face-on galaxies become systematically bluer with increasing radius. The radial photometry is compared to new dust extinction models and stellar population synthesis models. This comparison shows that the colour gradients in face-on galaxies are best explained by age and metallicity gradients in the stellar populations and that dust reddening plays a minor role. The colour gradients imply M/L gradients, making the `missing light' problem as derived from rotation curve fitting even worse.

  16. The colour of domestication and the designer chicken

    Science.gov (United States)

    Sheppy, Andrew

    2011-03-01

    Colour is an important feature of most living organisms. In the wild, colour has great significance affecting the survival and reproductive success of the species. The environmental constraints which lead to the specific colours of birds and animals are very strong and individuals of novel colours tend not to survive. Under domestication, mankind has transformed all the species involved which have thus been freed from environmental pressures to a large extent. Early colour variants were mostly selected for utility reasons or religious practices. In more recent centuries colour varieties have been created purely for ornament and pleasure, fashion playing a surprisingly large part in their development. A bewildering array of colours and patterns can now be found in all our commensal species, especially the Domestic Fowl ( Gallus gallus domesticus).

  17. Colour how we see it and sow we use it

    CERN Document Server

    Woolfson, Michael Mark

    2016-01-01

    Colour makes our lives more interesting how dull it would be in a black-and-white world! It pleases us aesthetically, entertains us and is useful to us. This unique book aims to describe the scientific nature of colour and light, and how we see it, in an accessible and easily understandable style. The evolution of the eye, science of colour and technical visual systems are all broken down into readable chapters, with clear images and illustrations provided for reference. The book then goes on to discuss the innate tendency of humankind to produce artistic works as conceived, realised and augmented through the use of colour. Focussing on broad forms of artistic entertainment painting with pigments and dyes, colour and light in photography and cinematography, light displays and colour in television this book then delivers a comprehensive review of what colour means and has meant in the creative arts.

  18. The theory and phenomenology of coloured quark models

    CERN Document Server

    Close, F E

    1975-01-01

    A general introduction to coloured quark models is given and their phenomenology is described with particular reference to the new particles. It is shown that there are essentially three types of colour models with colour excitation when the colour group is SU(3)- Han-Nambu, Greenberg and a model which has the same charges as that of Tati and which can be thought of as the Gell-Mann colour scheme with excitation of the colour degrees of freedom. Particular attention is paid to the four problems of colour models for psi phenomenology-the radiative decays, the G parity conservation, the lack of deep inelastic threshold phenomena and the apparent discovery of dileptons at SPEAR. (40 refs).

  19. Colour based sorting station with Matlab simulation

    Directory of Open Access Journals (Sweden)

    Constantin Victor

    2017-01-01

    Full Text Available The paper presents the design process and manufacturing elements of a colour-based sorting station. The system is comprised of a gravitational storage, which also contains the colour sensor. Parts are extracted using a linear pneumatic motor and are fed onto an electrically driven conveyor belt. Extraction of the parts is done at 4 points, using two pneumatic motors and a geared DC motor, while the 4th position is at the end of the belt. The mechanical parts of the system are manufactured using 3D printer technology, allowing for easy modification and adaption to the geometry of different parts. The paper shows all of the stages needed to design, optimize, test and implement the proposed solution. System optimization was performed using a graphical Matlab interface which also allows for sorting algorithm optimization.

  20. Colour dosemeters for high level radiation dosimetry

    DEFF Research Database (Denmark)

    Schönbacher, H.; Coninckx, F.; Miller, A.;

    1990-01-01

    interpretation or a dose measurement with a simple instrument such as a portable reflecting densitometer in the range of 10(3) to 10(6) Gy. Two projects were investigated: (1) a thin plastic film with a self adhesive tape containing a radiochromic dye which induces a colour change when exposed to ionising...... radiation; and (2) a paint containing a base substance with a pigment. The paint dosemeter remained unaffected by irradiation up to 3 x 10(4) Gy while the film dosemeter showed a measurable colour change from 10(4) Gy to 5 x 10(5) Gy. Above 10(6) Gy the film dosemeter is destroyed by radiation. Samples...

  1. Testing of Nonlinear Filters For Coloured Noise

    Science.gov (United States)

    Macek, Wieslaw M.; Redaelli, Stefano; Plewczynski, Dariusz

    We focus on nonlinearity and deterministic behaviour of classical model systems cor- rupted by white or coloured noise. Therefore, we use nonlinear filters to give a faith- ful representation of nonlinear behaviour of the systems. We also analyse time series of a real system, namely, we study velocities of of the solar wind plasma including Alfvénic fluctuations measured in situ by the Helios spacecraft in the inner helio- sphere. We demonstrate that the influence of white and coloured noise in the data records can be efficiently reduced by a nonlinear filter. We show that due to this non- linear noise reduction we get with much reliability estimates of the largest Lyapunov exponent and the Kolmogorov entropy.

  2. Colour-Charged Quark Matter in Astrophysics?

    Institute of Scientific and Technical Information of China (English)

    QIU Cong-Xin; XU Ren-Xin

    2006-01-01

    Colour confinement is only a supposition, which has not yet been proven in QCD. Here we propose that macroscopic quark-gluon plasma in astrophysics could hardly maintain colourless because of causality. It is expected that the existence of chromatic strange quark stars as well as chromatic strangelets preserved from the QCD phase transition in the early Universe could be unavoidable if their colourless correspondents do exist.

  3. Mushroom Processing Retaining Colour Without Losing Weight

    OpenAIRE

    Gormley, T. R. (Thomas Ronan); Walshe, P.E.

    1986-01-01

    Processed mushrooms must be blanched so that they will retain an acceptable white colour. However,. This can lead to a weight loss of between 20 and 30 per cent, which is bad economy for the processor. Research at Kinsealy Research Centre has come up with some solution for this problem. Breading of unblanched mushrooms prior to freezing is one. Another successful technique is to treat mushrooms with xanthan gum prior to blanching in the case of frozen or canned mushrooms.

  4. Constraining RRc candidates using SDSS colours

    CERN Document Server

    Bányai, E; Molnár, L; Dobos, L; Szabó, R

    2016-01-01

    The light variations of first-overtone RR Lyrae stars and contact eclipsing binaries can be difficult to distinguish. The Catalina Periodic Variable Star catalog contains several misclassified objects, despite the classification efforts by Drake et al. (2014). They used metallicity and surface gravity derived from spectroscopic data (from the SDSS database) to rule out binaries. Our aim is to further constrain the catalog using SDSS colours to estimate physical parameters for stars that did not have spectroscopic data.

  5. Light colour preference of growing rabbits

    Directory of Open Access Journals (Sweden)

    Zsolt Szendrő

    2010-01-01

    Full Text Available The objective of the experiment was to evaluate the light colour preference of growing rabbits placed in a free-choice cage. The experiment was carried out on 128 Pannon White growing rabbits weaned at the age of 5 weeks and placed into blocks (2m2 of four cages. The rabbits could move freely among the four cages (0.5m2 each through swing doors. The cages differed only in the colour of the light applied (white, yellow, green or blue. The lighting schedule was 16L: 8D. From 6 until 10 weeks of age, infrared video recording was performed once a week (24 hours. The number of rabbits in each cage was counted every 15 minutes. Feed consumption was measured weekly. Between 6 and 10 weeks of age the rabbits significantly preferred white light (28.0%. The preference order was the following: yellow (26.3%, blue (23.4% and green (22.3% (P<0.001. No significant differences were recorded in the feed consumption among the cages. In conclusion, the cage preference of the rabbits was slightly affected by the light colour.

  6. COLOUR IMAGE REPRESENTION OF MULTISPECTRAL IMAGE FUSION

    Directory of Open Access Journals (Sweden)

    Preema Mole

    2016-07-01

    Full Text Available The availability of imaging sensors operating in multiple spectral bands has led to the requirement of image fusion algorithms that would combine the image from these sensors in an efficient way to give an image that is more perceptible to human eye. Multispectral Image fusion is the process of combining images optically acquired in more than one spectral band. In this paper, we present a pixel-level image fusion that combines four images from four different spectral bands namely near infrared(0.76-0.90um, mid infrared(1.55-1.75um,thermal- infrared(10.4-12.5um and mid infrared(2.08-2.35um to give a composite colour image. The work coalesces a fusion technique that involves linear transformation based on Cholesky decomposition of the covariance matrix of source data that converts multispectral source images which are in grayscale into colour image. This work is composed of different segments that includes estimation of covariance matrix of images, cholesky decomposition and transformation ones. Finally, the fused colour image is compared with the fused image obtained by PCA transformation.

  7. The evolution of colour pattern complexity: selection for conspicuousness favours contrasting within-body colour combinations in lizards.

    Science.gov (United States)

    Pérez I de Lanuza, G; Font, E

    2016-05-01

    Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis, we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long-wavelength-based) and lateral (short-wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties.

  8. NICE: A Computational Solution to Close the Gap from Colour Perception to Colour Categorization.

    Science.gov (United States)

    Parraga, C Alejandro; Akbarinia, Arash

    2016-01-01

    The segmentation of visible electromagnetic radiation into chromatic categories by the human visual system has been extensively studied from a perceptual point of view, resulting in several colour appearance models. However, there is currently a void when it comes to relate these results to the physiological mechanisms that are known to shape the pre-cortical and cortical visual pathway. This work intends to begin to fill this void by proposing a new physiologically plausible model of colour categorization based on Neural Isoresponsive Colour Ellipsoids (NICE) in the cone-contrast space defined by the main directions of the visual signals entering the visual cortex. The model was adjusted to fit psychophysical measures that concentrate on the categorical boundaries and are consistent with the ellipsoidal isoresponse surfaces of visual cortical neurons. By revealing the shape of such categorical colour regions, our measures allow for a more precise and parsimonious description, connecting well-known early visual processing mechanisms to the less understood phenomenon of colour categorization. To test the feasibility of our method we applied it to exemplary images and a popular ground-truth chart obtaining labelling results that are better than those of current state-of-the-art algorithms.

  9. A universal ultraviolet-optical colour-colour-magnitude relation of galaxies

    CERN Document Server

    Chilingarian, Igor

    2011-01-01

    Although the optical colour-magnitude diagram of galaxies allows one to select red sequence objects, neither can it be used for galaxy classification without additional observational data such as spectra or high-resolution images, nor to identify blue galaxies at unknown redshifts. We show that adding the near ultraviolet colour to the optical CMD reveals a tight relation in the three-dimensional colour-colour-magnitude space smoothly continuing from the "blue cloud" to the "red sequence". We found that 98 per cent of 225,000 low-redshift (Z<0.27) galaxies follow a smooth surface g-r=F(M,NUV-r) with a standard deviation of 0.03-0.07 mag making it the tightest known galaxy photometric relation. There is a strong correlation between morphological types and integrated NUV-r colours. Rare galaxy classes such as E+A or tidally stripped systems become outliers that occupy distinct regions in the 3D parameter space. Using stellar population models for galaxies with different SFHs, we show that (a) the (NUV-r, g-r...

  10. Interactions between colour-producing mechanisms and their effects on the integumentary colour palette.

    Science.gov (United States)

    Shawkey, Matthew D; D'Alba, Liliana

    2017-07-05

    Animal integumentary coloration plays a crucial role in visual communication and camouflage, and varies extensively among and within species and populations. To understand the pressures underlying such diversity, it is essential to elucidate the mechanisms by which animals have created novel integumentary coloration. Colours can be produced by selective absorption of light by skin pigments, through light scattering by structured or unstructured tissues, or by a combination of pigments and nanostructures. In this review, we highlight our current understanding of the interactions between pigments and structural integumentary tissues and molecules. We analyse the available evidence suggesting that these combined mechanisms are capable of creating colours and optical properties unachievable by either mechanism alone, thereby effectively expanding the animal colour palette. Moreover, structural and pigmentary colour mechanisms frequently interact in unexpected and overlooked ways, suggesting that classification of colours as being of any particular type may be difficult. Finally, we discuss how these mixtures are useful for investigating the largely unknown genetic, developmental and physical processes generating phenotypic diversity.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

  11. Quantization Selection of Colour Histogram Bins to Categorize the Colour Appearance of Landscape Paintings for Image Retrieval

    Directory of Open Access Journals (Sweden)

    Aniza Othman

    2016-12-01

    Full Text Available In the world of today, most images are digitized and kept in digital libraries for better organization and management. With the growth of information and communication technology, collection holders such as museums or cultural institutions have been increasingly interested in making their collections available anytime and anywhere for any Image Retrieval (IR activities such as browsing and searching. In a colour image retrieval application, images retrieved by users are accomplished according to their specifications on what they want or acquire, which could be based upon so many concepts. We suggest an  approach to categorize the colour appearances of whole scene landscape painting images based on human colour perception. The colour features in the image are represented using a colour histogram. We then find  the suitable quantization bins that can be used to generate optimum colour histograms for all categories of colour appearances, which is selected based on theHarmonic Mean of the precision and recall,  also known as F-Score percentage higher saturated value. Colour appearance attributes in the CIELab colour model (L-Lightness, a and b are colour-opponent dimension are used to generate colour appearance feature vectors namely the saturation metric, lightness metric and multicoloured metric. For the categorizations, we use the Nearest Neighbour (NN method to detect the classes by using the predefined colour appearance descriptor measures and the pre-set thresholds.  The experimental results show that the quantization of CIELab colour model into 11 uniformly bins for each component had achieved the optimum result for all colour appearances categories.

  12. A simplified method for generation of pseudo natural colours from colour infrared aerial photos

    DEFF Research Database (Denmark)

    Knudsen, Thomas; Olsen, Brian Pilemann

    In spite of their high potential for automated discrimination between vegetation and human made objects, colour-infrared (CIR) aerial photos have not been in widespread use for traditional photogrammetric mapping. This is probably due to their awkward colour representation invalidating the visual...... analytical experience of the stereo analysts doing the actual registration of the topographical data. In this paper, we present a method for generating pseudo natural colour (PNC) representations from CIR photos. This enables the combination of automated vegetation discrimination with traditional manual...... mapping methods. The method presented is a dramatic simplification of a recently published method, going from a 7 step to a 2 step procedure. The first step is a classification of the input image into 4 domains, based on simple thresholding of a vegetation index and a saturation measure for each pixel...

  13. Metal free structural colours via disordered nanostructures with nm resolution and full CYMK colour spectrum

    KAUST Repository

    Bonifazi, Marcella

    2017-02-28

    Structural colours represents a research area of great interest, due to a wide field of application ranging from micro-security to biomimetic materials. At present metallic substrate are heavily employed and only a partial spectra of colours can be realised. We propose a novel, metal-free technology that exploits the complex scattering from a disordered three-dimensional dielectric material on a silicon substrate. We reproduce experimentally the full spectrum of CMYK colours, including variations in intensity. Our resolution lies in the nm range, limited only by the electron beam lithography fabrication process. We demonstrate that this technique is extremely robust, suitable for flexible and reusable substrates. Full of these notable proprieties these nano-structures fits perfectly with the requirements of a real-world technology.

  14. Minimum Perceptible Differences in the Colour Reproduction of Photographic Prints.

    Science.gov (United States)

    Wood, Carol Ann

    Available from UMI in association with The British Library. Electronic simulations of the Macbeth Color Checker Chart were prepared such that each of the eighteen colour patches could be varied independently from the rest of the chart. The output was in the form of photographic colour prints which comprised a ring-around set of 168 prints for each of the colour patches, where each print was a colour perturbation from a standard print. Twelve observers, with normal colour vision, judged the prints in each set to be perceptibly different or not perceptibly different from the standard print, for each patch. The experimental results, in the form of hue-orientated and non hue-orientated ellipses, were compared with MacAdam type ellipses, CIELAB unit ellipses and ellipses derived from the CMC(1:c) colour difference formula: the comparisons were made in the 1976 CIELAB colour space. Colour reproduction indices were calculated for the end points of the semi-major and semi-minor axes of the CMC ellipses, for each of the eighteen colour patches. The coefficient of variation was very small for the combined hue index, the combined chroma index and the overall combined index, indicating that the mean values for these indices could be assigned to any of the ellipses as a measure of the minimum perceptible difference in terms of colour appearance.

  15. Can Grapheme-Colour Synaesthesia be Induced by Hypnosis?

    Directory of Open Access Journals (Sweden)

    Hazel Patricia Anderson

    2014-04-01

    Full Text Available Grapheme-colour synaesthesia is a perceptual experience where graphemes, letters or words evoke a specific colour, which are experienced either as spatially coincident with the grapheme inducer (projector sub-type or elsewhere, perhaps without a definite spatial location (associator sub-type. Here, we address the question of whether synaesthesia can be rapidly produced using a hypnotic colour suggestion to examine the possibility of ‘hypnotic synaesthesia’, i.e. subjectively experienced colour hallucinations similar to those experienced by projector synaesthetes. We assess the efficacy of this intervention using an embedded figures test, in which participants are required to detect a shape (e.g., a square composed of local graphemic elements. For grapheme-colour synaesthetes, better performance on the task has been linked to a higher proportion of graphemes perceived as coloured. We found no performance benefits on this test when using a hypnotic suggestion, as compared to a no-suggestion control condition. The same result was found when participants were separated according to the degree to which they were susceptible to the suggestion (number of coloured trials perceived. However, we found a relationship between accuracy and subjective reports of colour in those participants who reported a large proportion of coloured trials: trials in which the embedded figure was accurately recognised (relative to trials in which it was not were associated with reports of more intense colours occupying a greater spatial extent. Collectively, this implies that hypnotic colour was only perceived after shape detection rather than aiding in shape detection via colour-based perceptual grouping. The results suggest that hypnotically induced colours are not directly comparable to synaesthetic ones.

  16. Colour-rendition properties of solid-state lamps

    Science.gov (United States)

    Žukauskas, A.; Vaicekauskas, R.; Shur, M. S.

    2010-09-01

    The applicability of colour-quality metrics to solid-state light sources is validated and the results of the assessment of colour-rendition characteristics of various lamps are presented. The standard colour-rendering index metric or a refined colour-quality scale metric fails to distinguish between two principle colour-rendition properties of illumination: the ability to render object colours with high fidelity and the ability to increase chromatic contrast, especially when the spectra of light sources contain a few narrow-band electroluminescence components. Supplementing these metrics by the known figures of merit that measure the gamut area of a small number of test colour samples does not completely resolve this issue. In contrast, the statistical approach, which is based on sorting a very large number of test colour samples in respect of just-perceivable colour distortions of several kinds, offers a comprehensive assessment of colour-rendition properties of solid-state light sources. In particular, two statistical indices, colour-fidelity index (CFI) and colour-saturation index (CSI), which are the relative numbers of object colours rendered with high fidelity and increased saturation, respectively, are sufficient to reveal and assess three distinct types of solid-state light sources. These are (i) high-fidelity lamps, which cover the entire spectrum with the spectral components present in the wavelength ranges of both 530-610 nm and beyond 610 nm (e.g. trichromatic warm white phosphor-converted (pc) light-emitting diodes (LEDs), red-amber-green-blue LED clusters, complementary clusters of white and coloured LEDs); (ii) colour-saturating lamps, which lack power in the 530-610 nm wavelength range (e.g. red-green-blue or red-cyan-blue LED clusters) and (iii) colour-dulling lamps, which lack power for wavelengths longer than 610 nm (dichromatic daylight pc LEDs and amber-green-blue LED clusters). Owing to a single statistical format, CSI and CFI can be used for

  17. Research on reality map colour design computer model

    Institute of Scientific and Technical Information of China (English)

    刘书楼; 陈宝雯; 刘天舒; 施祖辉; 卢峰; 韩培军; 刘冰

    1995-01-01

    Through the crucial techniques and technical difficulties of the research on reality map colour design computer model (RMCDCM), based on the principle of chromatics and the experimental analysis, a new model about the transformation between CMY ink printing and RGB screen colours and RMCDCM is set up In the chromatics, there is a general concept that the range of RGB screen colours is larger than that of printing colours. The concept is exactly explained. It not only accounts for the erroneous phenomena from the theory which are produced when CRT monitor, PAL and NTSC models reproduce printing colour standards, but also solves the technical problems from the methodology which long exist in the research for screen reproduction and printing restoration of printing colour standards. A theoretical basis is provided.

  18. Human eye colour and HERC2, OCA2 and MATP

    DEFF Research Database (Denmark)

    Mengel-From, Jonas; Børsting, Claus; Sanchez, Juan J.

    2010-01-01

    Prediction of human eye colour by forensic genetic methods is of great value in certain crime investigations. Strong associations between blue/brown eye colour and the SNP loci rs1129038 and rs12913832 in the HERC2 gene were recently described. Weaker associations between eye colour and other...... value of typing either the HERC2 SNPs rs1129038 and/or rs12913832 that are in strong linkage disequilibrium was observed when eye colour was divided into two groups, (1) blue, grey and green (light) and (2) brown and hazel (dark). Sequence variations in rs11636232 and rs7170852 in HERC2, rs1800407...... in OCA2 and rs16891982 in MATP showed additional association with eye colours in addition to the effect of HERC2 rs1129038. Diplotype analysis of three sequence variations in HERC2 and one sequence variation in OCA2 showed the best discrimination between light and dark eye colours with a likelihood ratio...

  19. Coat colour changes associated with cabergoline administration in bitches.

    Science.gov (United States)

    Gobello, C; Castex, G; Broglia, G; Corrada, Y

    2003-08-01

    Cabergoline or bromocriptine were administered orally to 60 bitches at doses of 5 microg/kg and 15 microg/kg daily, respectively, for two to 45 days for the treatment of pseudopregnancy or for oestrus induction. Seven of the dogs which received cabergoline for more than 14 days developed coat colour changes from the second week of administration to the next coat shedding. Of these, fawn-coloured bitches developed a yellowish coat colour while Argentine boar hounds became black spotted, mainly on their extremities. In previous untreated oestrous periods, these bitches had shown no coat colour changes. It is concluded that a colour shift in certain haircoats of particular breeds could be mediated through the inhibition of the secretion of melanocyte-stimulating hormone by the administration of the dopaminergic agonist cabergoline for more than two weeks. Transient coat colour changes should be considered a possible side effect when planning long-term treatment with dopaminergic agonists in dogs.

  20. Colour changes by laser irradiation of reddish building limestones

    Energy Technology Data Exchange (ETDEWEB)

    Grossi, C.M., E-mail: c.grossi-sampedro@uea.ac.uk [School of Health Sciences, University of East Anglia, Norwich NR4 7TJ (United Kingdom); Benavente, D. [Department of Earth and Environment Sciences, University of Alicante. 03690 Alicante (Spain)

    2016-10-30

    Highlights: • This is the first time that XPS is used to determine the cause of colour change in coloured stones when cleaned with laser at 1064 nm. • We demonstrate that the colour change in red limestones is due to a reduction in the state of oxidation of iron, in this case present as hematite. • XPS could be routinely used to analyse causes of colour changes during laser cleaning in other types of coloured building stones. - Abstract: We have used X-ray photoelectron spectroscopy (XPS) as a novel method to investigate the causes of colour changes in a reddish limestone under irradiation by a Q-switched Nd:YAG 1064 nm laser. We irradiated clean dry and wet surfaces of Pidramuelle Roja, a building stone frequently used in the Asturian heritage, at fluences ranging from 0.12 to 1.47 J cm{sup −2}. We measured the colour coordinates and undertook XPS analysis of the state of oxidation of iron both before and after irradiation. Visible colour changes and potential aesthetic damage occurred on dry surfaces from a fluence of 0.31 J cm{sup −2}, with the stone showing a greening effect and very intense darkening. The colour change on dry surfaces was considerably higher than on wet surfaces, which at the highest fluence (1.47 J cm{sup −2}) was also above the human visual detection threshold. The use of XPS demonstrated that the change in colour (chroma and hue) is associated with a reduction in the iron oxidation state on dry surfaces during laser irradiation. This points out to a potential routinary use of XPS to analyse causes of colour changes during laser cleaning in other types of coloured building stones.

  1. Genetics and evolution of colour patterns in reptiles.

    Science.gov (United States)

    Olsson, Mats; Stuart-Fox, Devi; Ballen, Cissy

    2013-01-01

    The study of coloration in the polyphyletic reptilians has flourished in the last two decades, in particular with respect to the underlying genetics of colour traits, the function of colours in social interactions, and ongoing selection on these traits in the wild. The taxonomic bias, however, is profound: at this level of resolution almost all available information is for diurnal lizards. Therefore, we focus on case studies, for which there are as complete causal sequences of colour evolution as possible, from phenotypic expression of variation in colour, to ongoing selection in the wild. For work prior to 1992 and for a broader coverage of reptilian coloration we refer the readers to Cooper and Greenburg's (Biology of the Reptilia, 1992) review. There are seven major conclusions we would like to emphasise: (a) visual systems in diurnal lizards are broadly conserved but among the wider range of reptiles in general, there is functionally important variation in the number and type of photoreceptors, spectral tuning of photopigments and optical properties of the eye; (b) coloration in reptiles is a function of complex interactions between structural and pigmentary components, with implications for both proximate control and condition dependence of colour expression; (c) studies of colour-variable species have enabled estimates of heritability of colour and colour patterns, which often show a simple Mendelian pattern of inheritance; (d) colour-polymorphic lizard species sometimes, but not always, show striking differences in genetically encoded reproductive tactics and provide useful models for studying the evolution and maintenance of polymorphism; (e) both male and female colours are sometimes, but not always, a significant component of socio-sexual signalling, often based on multiple traits; (f) evidence for effects of hormones and condition on colour expression, and trade-offs with immunocompetence and parasite load, is variable; (g) lizards show fading of colours

  2. Red, black or white? The dawn of colour symbolism

    Directory of Open Access Journals (Sweden)

    Simona Petru

    2006-12-01

    Full Text Available In this paper the use of the pigments in the Paleolithic is presented, and some ideas of the symbolic meaning of colours are suggested. The colour red might have been a symbol of transformation, and as such, it was used in burials and for painting the Venus figurines. In the Slovenian Paleolithic, there is scant evidence of importance of colour and only a few finds of stones used for the grinding of the red pigment have been found.

  3. Colour particle states behaviour in the QCD vacuum

    Directory of Open Access Journals (Sweden)

    Kuvshinov V.I.

    2016-01-01

    The behaviour of squeezed and entangled quantum states, the interaction of colour superpositions and multiparticle states with stochastic QCD vacuum is described. It is shown that it leads to a fully mixed quantum state with equal probabilities for different colours. Decoherence rate is found to be proportional to the product of the distance between colour charges and the time during which this interaction has taken place. I.e. such an interaction seems to lead naturally to confinement of quarks.

  4. COLOUR TERMS IN MODERN LINGUISTICS: SEMANTIC AND SEMIOTIC ASPECTS

    Directory of Open Access Journals (Sweden)

    E. V. SAPIGA

    2016-01-01

    Full Text Available The article is devoted to the study of colour terms in modern linguistics, and in particular its semantic and semiotic aspects. The aim of the article is to identify the lexical-semantic features of colour terms in the definition of national cultural identity of linguistic and speech means. Special attention is paid to semantic diversity of colour symbolism, which is closely related to psychological perception and has numerous crosscultural differences in relation to the events in people's lives. The article analyzes the so-called colour vocabulary, namely, the colour -indication, describing shades of colour that have a narrative structure and are in direct and additional value. In particular, we take into account the metaphorical reconsiderations of the peripheral color-namings and color terms, which include, for example, borrowed and terminological adjectives, neologisms, archaisms, nonce words etc. From the point of view of belonging the colorindication to different parts of speech, a significant group is made by adjectives , suffixal formation, etc. The lexico-semantic field of colour has a high degree of organization. Modern researches of determining the nature of lexical-semantic field of colour terms confirm the presence of about ten pigment genes, which are individual for each person. A defined set of pigment genes allows a person to perceive colour and its shades in different ways. Observations of colour perception in people of different cultures discover the dependence and the relationship between concepts and words in various systems, which explain the differences in the reactions to colour and the absence of a specific hue in different cultures. The analysis revealed the close relationship of colour symbolism with a mental and psychological component that reflects the moods, the reality and situation-specific nature of the occurring phenomena.

  5. Multicolour interphase cytogenetics: 24 chromosome probes, 6 colours, 4 layers

    OpenAIRE

    2011-01-01

    From the late 1980s onwards, the use of DNA probes to visualise sequences on individual chromosomes (fluorescent in-situ hybridisation - FISH) revolutionised the study of cytogenetics. Following single colour experiments, more fluorochromes were added, culminating in a 24 colour assay that could distinguish all human chromosomes. Interphase cytogenetics (the detection of chromosome copy number in interphase nuclei) soon followed, however 24 colour experiments are hampered for this application...

  6. FIR colours and SEDs of nearby galaxies observed with Herschel

    OpenAIRE

    Boselli, A.; Bock, J.; Bradford, M; Fadda, D.; Levenson, L.; Lu, N.; Schulz, B.; Wright, G.

    2010-01-01

    We present infrared colours (in the 25−500 μm spectral range) and UV to radio continuum spectral energy distributions of a sample of 51 nearby galaxies observed with SPIRE on Herschel. The observed sample includes all morphological classes, from quiescent ellipticals to active starbursts. Active galaxies have warmer colour temperatures than normal spirals. In ellipticals hosting a radio galaxy, the far-infrared (FIR) emission is dominated by the synchrotron nuclear emission. The colour temper...

  7. Perceptual organization in colour perception: Inverting the gamut expansion effect.

    Science.gov (United States)

    Ekroll, Vebjørn; Faul, Franz

    2013-01-01

    In the well-known gamut expansion effect, uniformly coloured target patches are perceived as more colourful when they are embedded in a uniform grey surround than when they are embedded in a variegated one. Here, we provide a demonstration showing that this effect can be inverted when the uniformly coloured target patches are replaced by variegated ones. This observation suggests that the gamut expansion effect is due to mechanisms of transparency perception rather than due to contrast adaptation.

  8. Perceptual Organization in Colour Perception: Inverting the Gamut Expansion Effect

    Directory of Open Access Journals (Sweden)

    Vebjørn Ekroll

    2013-08-01

    Full Text Available In the well-known gamut expansion effect, uniformly coloured target patches are perceived as more colourful when they are embedded in a uniform grey surround than when they are embedded in a variegated one. Here, we provide a demonstration showing that this effect can be inverted when the uniformly coloured target patches are replaced by variegated ones. This observation suggests that the gamut expansion effect is due to mechanisms of transparency perception rather than due to contrast adaptation.

  9. FIR colours and SEDs of nearby galaxies observed with Herschel

    OpenAIRE

    Boselli, A.; Ciesla, L.; Buat, V.; Cortese, L.; Auld, R.; Baes, Maarten; Bendo, GJ; S. Bianchi; Bock, J.; Bomans, DJ; Bradford, M; Castro-Rodriguez, N.; Chanial, P.; Charlot, S.; Clemens, M.

    2010-01-01

    We present infrared colours (in the 25-500 mu m spectral range) and UV to radio continuum spectral energy distributions of a sample of 51 nearby galaxies observed with SPIRE on Herschel. The observed sample includes all morphological classes, from quiescent ellipticals to active starbursts. Active galaxies have warmer colour temperatures than normal spirals. In ellipticals hosting a radio galaxy, the far-infrared (FIR) emission is dominated by the synchrotron nuclear emission. The colour temp...

  10. Colour characteristics of winter wheat grits of different grain size

    Directory of Open Access Journals (Sweden)

    Horváth Zs. H.

    2015-01-01

    Full Text Available Nowadays, wheat has spread all over the world due to its extensive usability. The colour of wheat grits is very important for the milling and baking industry because it determines the colour of the products made from it. The instrumental colour measuring is used, first of all, for durum wheat. We investigated the relationship between colour characteristics and grain size in the case of different hard aestivum wheats. We determined the colour using the CIE (Commission Internationale de l’Eclairage 1976 L*, a*, b* colour system measured by MINOLTA CR-300 tristimulus colorimeter. After screening the colour of the wheat fractions of different grain size, grits was measured wet and dry. We determined the L*, a*, b* colour co-ordinates and the whiteness index, too. To evaluate the values we had obtained, we used analysis of variance and regression analysis. We pointed out that the colour of wheat grits of different grain size is dependent on the hardness index of wheat. The lightness co-ordinate (L* of grits of the harder wheat is smaller, while a* and b* co-ordinates are higher. We also found that while grain size rises, the L* co-ordinate decreases and a*, b* values increase in the case of every type of wheat. The colour of grits is determined by the colour of fractions of 250-400 μm in size, independently from the average grain size. The whiteness index and the L* colour co-ordinate have a linear relation (R2 = 0.9151; so, the determination of whiteness index is not necessary. The L* value right characterizes the whiteness of grits.

  11. Factor structure of Raven's Coloured Progressive Matrices

    OpenAIRE

    Muniz, Monalisa; Gomes, Cristiano Mauro Assis; Pasian, Sonia Regina

    2016-01-01

    Abstract This study's objective was to verify the factor structure of Raven's Coloured Progressive Matrices (CPM). The database used included the responses of 1,279 children, 50.2% of which were males with an average age of 8.48 years old and a standard deviation of 1.49 yrs. Confirmatory factor analyses were run to test seven models based on CPM theory and on a Brazilian study addressing the test's structure. The results did not confirm the CPM theoretical proposition concerning the scales b...

  12. Phase transitions in dense 2-colour QCD

    CERN Document Server

    Boz, Tamer; Fister, Leonard; Skullerud, Jon-Ivar

    2013-01-01

    We investigate 2-colour QCD with 2 flavours of Wilson fermion at nonzero temperature T and quark chemical potential mu, with a pion mass of 700 MeV (m_pi/m_rho=0.8). From temperature scans at fixed mu we find that the critical temperature for the superfluid to normal transition depends only very weakly on mu above the onset chemical potential, while the deconfinement crossover temperature is clearly decreasing with mu. We also present results for the Landau-gauge gluon propagator in the hot and dense medium.

  13. Age differences on Raven's Coloured Progressive Matrices.

    Science.gov (United States)

    Panek, P E; Stoner, S B

    1980-06-01

    Raven's Coloured Progressive Matrices was administered to 150 subjects (75 males, 75 females) ranging in age from 20 to 86 yr. Subjects were placed into one of three age groups: adult (M age = 27.04 yr.), middle-age (M age = 53.36 yr.), old (M age = 73.78 yr.), with 25 males and 25 females in each age group. Significant differences between age groups on the matrices were obtained after partialing out the effects of educational level, while sex of subject was not significant.

  14. Colour variations of Comet C/2013 UQ4 (Catalina)

    Science.gov (United States)

    Ivanova, Oleksandra; Zubko, Evgenij; Videen, Gorden; Mommert, Michael; Hora, Joseph L.; Krišandová, Zuzana Seman; Svoreň, Ján; Novichonok, Artyom; Borysenko, Serhii; Shubina, Olena

    2017-08-01

    We report observations of colour in the inner coma of Comet C/2013 UQ4 (Catalina) with the broad-band B and R filters. We find significant temporal variations of the colour slope, ranging from -12.67 ± 8.16% per 0.1 μm to 35.09 ± 11.70% per 0.1 μm. It is significant that the comet changes colour from red to blue over a period of only 2 d. Such dispersion cannot be characterized with an average colour slope. We also observe Comet C/2013 UQ4 (Catalina) in infrared using Spitzer and find no significant CO/CO2 gaseous species in its coma. Therefore, we classify Comet C/2013 UQ4 (Catalina) as a dust-rich comet and attribute the measured colour slope to its dust. We analyse the colour slope using the model of agglomerated debris particles and conclude that the C/2013 UQ4 coma was chemically heterogeneous, consisting of at least two components. The first component producing the bluest colour is consistent with Mg-rich silicates. There are three different options for the second component producing the reddest colour. This colour is consistent with either Mg-Fe silicates, kerogen type II or organic matter processed with a low dose of ultraviolet radiation.

  15. Spatio-temporal colour correction of strongly degraded movies

    Science.gov (United States)

    Islam, A. B. M. Tariqul; Farup, Ivar

    2011-01-01

    The archives of motion pictures represent an important part of precious cultural heritage. Unfortunately, these cinematography collections are vulnerable to different distortions such as colour fading which is beyond the capability of photochemical restoration process. Spatial colour algorithms-Retinex and ACE provide helpful tool in restoring strongly degraded colour films but, there are some challenges associated with these algorithms. We present an automatic colour correction technique for digital colour restoration of strongly degraded movie material. The method is based upon the existing STRESS algorithm. In order to cope with the problem of highly correlated colour channels, we implemented a preprocessing step in which saturation enhancement is performed in a PCA space. Spatial colour algorithms tend to emphasize all details in the images, including dust and scratches. Surprisingly, we found that the presence of these defects does not affect the behaviour of the colour correction algorithm. Although the STRESS algorithm is already in itself more efficient than traditional spatial colour algorithms, it is still computationally expensive. To speed it up further, we went beyond the spatial domain of the frames and extended the algorithm to the temporal domain. This way, we were able to achieve an 80 percent reduction of the computational time compared to processing every single frame individually. We performed two user experiments and found that the visual quality of the resulting frames was significantly better than with existing methods. Thus, our method outperforms the existing ones in terms of both visual quality and computational efficiency.

  16. Development of a forensic skin colour predictive test.

    Science.gov (United States)

    Maroñas, Olalla; Phillips, Chris; Söchtig, Jens; Gomez-Tato, Antonio; Cruz, Raquel; Alvarez-Dios, José; de Cal, María Casares; Ruiz, Yarimar; Fondevila, Manuel; Carracedo, Ángel; Lareu, María V

    2014-11-01

    There is growing interest in skin colour prediction in the forensic field. However, a lack of consensus approaches for recording skin colour phenotype plus the complicating factors of epistatic effects, environmental influences such as exposure to the sun and unidentified genetic variants, present difficulties for the development of a forensic skin colour predictive test centred on the most strongly associated SNPs. Previous studies have analysed skin colour variation in single unadmixed population groups, including South Asians (Stokowski et al., 2007, Am. J. Hum. Genet, 81: 1119-32) and Europeans (Jacobs et al., 2013, Hum Genet. 132: 147-58). Nevertheless, a major challenge lies in the analysis of skin colour in admixed individuals, where co-ancestry proportions do not necessarily dictate any one person's skin colour. Our study sought to analyse genetic differences between African, European and admixed African-European subjects where direct spectrometric measurements and photographs of skin colour were made in parallel. We identified strong associations to skin colour variation in the subjects studied from a pigmentation SNP discovery panel of 59 markers and developed a forensic online classifier based on naïve Bayes analysis of the SNP profiles made. A skin colour predictive test is described using the ten most strongly associated SNPs in 8 genes linked to skin pigmentation variation. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Camouflage through colour change: mechanisms, adaptive value and ecological significance.

    Science.gov (United States)

    Duarte, Rafael C; Flores, Augusto A V; Stevens, Martin

    2017-07-05

    Animals from a wide range of taxonomic groups are capable of colour change, of which camouflage is one of the main functions. A considerable amount of past work on this subject has investigated species capable of extremely rapid colour change (in seconds). However, relatively slow colour change (over hours, days, weeks and months), as well as changes arising via developmental plasticity are probably more common than rapid changes, yet less studied. We discuss three key areas of colour change and camouflage. First, we review the mechanisms underpinning colour change and developmental plasticity for camouflage, including cellular processes, visual feedback, hormonal control and dietary factors. Second, we discuss the adaptive value of colour change for camouflage, including the use of different camouflage types. Third, we discuss the evolutionary-ecological implications of colour change for concealment, including what it can tell us about intraspecific colour diversity, morph-specific strategies, and matching to different environments and microhabitats. Throughout, we discuss key unresolved questions and present directions for future work, and highlight how colour change facilitates camouflage among habitats and arises when animals are faced with environmental changes occurring over a range of spatial and temporal scales.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Authors.

  18. Analysis of organic colouring and binding components in colour layer of art works.

    Science.gov (United States)

    Kuckova, S; Nemec, I; Hynek, R; Hradilova, J; Grygar, T

    2005-05-01

    Two methods of analysis of organic components of colour layers of art works have been tested: IR microspectroscopy of indigo, Cu-phthalocyanine, and Prussian blue, and MALDI-TOF-MS of proteinaceous binders and a protein-containing red dye. The IR spectra distortion common for smooth outer surfaces and polished cross sections of colour layer of art works is suppressed by reflectance measurement of microtome slices. The detection limit of the three blue pigments examined is approximately 0.3 wt% in reference colour layers in linseed oil binder with calcite as extender and lead white as a drying agent. The sensitivity has been sufficient to identify Prussian blue in repaints on a Gothic painting. MALDI-TOF-MS has been used to identify proteinaceous binders in two historical paintings, namely isinglass (fish glue) and rabbit glue. MALDI-TOF-MS has also been proposed for identification of an insect red dye, cochineal carmine, according to its specific protein component. The enzymatic cleavage with trypsin before MALDI-TOF-MS seems to be a very gentle and specific way of dissolution of the colour layers highly polymerised due to very long aging of old, e.g. medieval, samples.

  19. The SAURON Project - XX. The Spitzer [3.6] - [4.5] colour in early-type galaxies: colours, colour gradients and inverted scaling relations

    CERN Document Server

    Peletier, Reynier F; van der Wolk, Guido; Falcon-Barroso, Jesus; Bacon, Roland; Bureau, Martin; Cappellari, Michele; Davies, Roger L; de Zeeuw, P Tim; Emsellem, Eric; Krajnovic, Davor; Kuntschner, Harald; McDermid, Richard M; Sarzi, Marc; Scott, Nicholas; Shapiro, Kristen L; Bosch, Remco C E van den; van de Ven, Glenn

    2011-01-01

    We investigate the [3.6] - [4.5] Spitzer-IRAC colour behaviour of the early-type galaxies of the SAURON survey, a representative sample of 48 nearby ellipticals and lenticulars. We investigate how this colour, which is unaffected by dust extinction, can be used to constrain the stellar populations in these galaxies. We find a tight relation between the [3.6]-[4.5] colour and effective velocity dispersion, a good mass-indicator in early-type galaxies. Contrary to other colours in the optical and near-infrared, we find that the colours become bluer for larger galaxies. The relations are tighter when using the colour inside r_e, rather than the much smaller r_e/8 aperture, due to the presence of young populations in the central regions. We also obtain strong correlations between the [3.6]-[4.5] colour and 3 strong absorption lines (H beta, Mg b and Fe 5015). Comparing our data with the models of Marigo et al., which show that more metal rich galaxies are bluer, we can explain our results in a way consistent with...

  20. Hair colouring, permanent styling and hair structure.

    Science.gov (United States)

    Harrison, S; Sinclair, R

    2003-07-01

    Hair is an important component of body image and has immense psychological importance for both men and women. Women, in particular, over the ages have modified their appearance through changing their hair colour or style. Hair can be straight, wavy or curly, blonde, black, brown or red. These natural variations are an important part of our identity that can be manipulated according to the dictates of fashion, culture or society. Different types of hair have varying affinity for the different colouring and waving methods. Damaged hair also has a different affinity for hair products than normal healthy hair. The hair shaft is remarkably strong and resistant to the extremes of nature. Hair cosmetics are widely available and manipulate the structural properties of hair. Whilst most procedures are safe, there is considerable potential for damage to the hair and hair problems of acute onset, including hair breakage, hair loss and loss of condition, are frequently blamed on the last product used on the hair. Hair problems are particularly prevalent among people who repeatedly alter the natural style of their hair.

  1. Ultraviolet colour opponency in the turtle retina.

    Science.gov (United States)

    Ventura, D F; Zana, Y; de Souza, J M; DeVoe, R D

    2001-07-01

    We have examined the functional architecture of the turtle Pseudemys scripta elegans retina with respect to colour processing, extending spectral stimulation into the ultraviolet, which has not been studied previously in the inner retina. We addressed two questions. (i) Is it possible to deduce the ultraviolet cone spectral sensitivity function through horizontal cell responses? (ii) Is there evidence for tetrachromatic neural mechanisms, i.e. UV/S response opponency? Using a constant response methodology we have isolated the ultraviolet cone input into the S/LM horizontal cell type and described it in fine detail. Monophasic (luminosity), biphasic L/M (red-green) and triphasic S/LM (yellow-blue) horizontal cells responded strongly to ultraviolet light. The blue-adapted spectral sensitivity function of a S/LM cell peaked in the ultraviolet and could be fitted to a porphyropsin cone template with a peak at 372 nm. In the inner retina eight different combinations of spectral opponency were found in the centre of the receptive field of ganglion cells. Among amacrine cells the only types found were UVSM-L+ and its reverse. One amacrine and four ganglion cells were also opponent in the receptive field surround. UV/S opponency, seen in three different types of ganglion cell, provides a neural basis for discrimination of ultraviolet colours. In conclusion, the results strongly suggest that there is an ultraviolet channel and a neural basis for tetrachromacy in the turtle retina.

  2. Chemical Deinking Flotation Efficiency Of Coloured Toner

    Directory of Open Access Journals (Sweden)

    Zeljka Barbaric-Mikocevic

    2009-11-01

    Full Text Available Recycling of paper printed with colour laser printer xerox phaser 7700 has been investigated in this work. The recycling was performed by chemical deinking with double stage flotation with the usage of anion surfactant. Froths collected by flotation were re-floated in purpose to increase the usage of fibers. The efficiency of first flotation of magenta particles (98.3%, cyan (96.9% and carbon ones (91.5% was calculated from results of the image analysis method. The same method was not effective for the identification of the yellow toner particles. The particle size is important characteristic for flotation efficiency. The efficiency of the first flotation is the best for smallest particles (magenta and for them the second flotation is unnecessary, while for bigger toner particles (cyan, carbon second flotation is desirable. The efficiency of second (abf flotation as a function of each colour (cyan 78.0%, magenta 58.6% and carbon 61.4% of particle number detected by image analysis method has shown that double stage flotation is successful method of improving the usage of fibres in recycling process.

  3. Chemical Deinking Flotation Efficiency Of Coloured Toner

    Directory of Open Access Journals (Sweden)

    Višnja Mikac Dadić

    2009-01-01

    Full Text Available Recycling of paper printed with colour laser printer xerox phaser 7700 has been investigated in this work. The recycling was performed by chemical deinking with double stage flotation with the usage of anion surfactant. Froths collected by flotation were re-floated in purpose to increase the usage of fibers. The efficiency of first flotation of magenta particles (98.3%, cyan (96.9% and carbon ones (91.5% was calculated from results of the image analysis method. The same method was not effective for the identification of the yellow toner particles. The particle size is important characteristic for flotation efficiency. The efficiency of the first flotation is the best for smallest particles (magenta and for them the second flotation is unnecessary, while for bigger toner particles (cyan, carbon second flotation is desirable. The efficiency of second (abf flotation as a function of each colour (cyan 78.0%, magenta 58.6% and carbon 61.4% of particle number detected by image analysis method has shown that double stage flotation is successful method of improving the usage of fibers in recycling process.

  4. The colour of galaxies in distant groups

    CERN Document Server

    Balogh, Michael L; Wilman, Dave; Bower, Richard G; Hau, George; Morris, Simon L; Mulchaey, J S; Oemler, A; Parker, Laura; Gwyn, Stephen

    2009-01-01

    (Abridged) We present new optical and near-infrared imaging for a sample of 98 spectroscopically-selected galaxy groups at 0.25colours for group members and the surrounding field population, statistically complete above a stellar mass limit of M=1E10 Msun. The overall colour distribution is bimodal in both the field and group samples; but at fixed luminosity the fraction of group galaxies populating the red peak is larger, by 20+/-7 per cent, than that of the field. In particular, group members with early-type morphologies, as identified in HST imaging, exhibit a tight red sequence, similar to that seen for more massive clusters. We show that approximately 20-30 per cent of galaxies on the red sequence may be dust-reddened galaxies with non-negligible star formation and early-spiral morphologies. This is true of both the field and group sample, and shows little dependence on near infrared luminosity. Thus, the fraction of bright group members with no sign of star formation o...

  5. LEARNING VOCABULARY THROUGH COLOURFUL PUZZLE GAME

    Directory of Open Access Journals (Sweden)

    Risca Dwiaryanti

    2014-05-01

    Full Text Available Vocabulary plays an important role because it links to the four skills of listening, speaking, reading, and writing. Those aspects should be integrated in teaching and learning process of English. However, the students must be able to know the meaning of each word or vocabulary of English in order to master the four skills. It is as a mean to create a sentence in daily communication to show someone’s feeling, opinion, idea, desire, etc. So that, both speakers understand what the other speaker mean. However, English as a second language in Indonesia seems very hard for the students to master vocabulary of English. It makes them not easy to be understood directly and speak fluently. The students, sometimes, get difficulties in understanding, memorizing the meaning of the vocabulary, and getting confused in using the new words. There must be an effective strategy to attract students’ interest, break the boredom, and make the class more lively. Based on the writer experience, Colourful Puzzle Game is able to make the students learn vocabulary quickly. It needs teacher’s creativity to create the materials of this game based on the class condition. The teacher just need a game board made from colourful papers, write any command and prohibition words on it. A dice is a tool to decide where the player should stop based on the number. Some pins as counter as sign of each player.

  6. Dynamic miniature lighting system with low correlated colour temperature and high colour rendering index for museum lighting of fragile artefacts

    DEFF Research Database (Denmark)

    Thorseth, Anders; Corell, Dennis Dan; Poulsen, Peter Behrensdorff

    2013-01-01

    Illumination of fragile and irreplaceable historical objects exhibited to the public presents challenges with regards to: good colour rendering, low photochemical degradation of sensitive materials and general energy consumption. We present a dynamic tri-colour LED lighting system for illumination...... of historical artefacts in display cases at museums and other exhibitions, which can replace 3-5 Watt incandescent light bulbs with a correlated colour temperature (CCT) from 2000 K to 2400 K. The solution decreases the energy consumption by up to 80 %, while maintaining colour rendering indices (Ra) above 90...

  7. Fusion of colour and monochromatic images with edge emphasis

    Directory of Open Access Journals (Sweden)

    Rade M. Pavlović

    2014-02-01

    Full Text Available We propose a novel method to fuse true colour images with monochromatic non-visible range images that seeks to encode important structural information from monochromatic images efficiently but also preserve the natural appearance of the available true chromacity information. We utilise the β colour opponency channel of the lαβ colour as the domain to fuse information from the monochromatic input into the colour input by the way of robust grayscale fusion. This is followed by an effective gradient structure visualisation step that enhances the visibility of monochromatic information in the final colour fused image. Images fused using this method preserve their natural appearance and chromacity better than conventional methods while at the same time clearly encode structural information from the monochormatic input. This is demonstrated on a number of well-known true colour fusion examples and confirmed by the results of subjective trials on the data from several colour fusion scenarios. Introduction The goal of image fusion can be broadly defined as: the representation of visual information contained in a number of input images into a single fused image without distortion or loss of information. In practice, however, a representation of all available information from multiple inputs in a single image is almost impossible and fusion is generally a data reduction task.  One of the sensors usually provides a true colour image that by definition has all of its data dimensions already populated by the spatial and chromatic information. Fusing such images with information from monochromatic inputs in a conventional manner can severely affect natural appearance of the fused image. This is a difficult problem and partly the reason why colour fusion received only a fraction of the attention than better behaved grayscale fusion even long after colour sensors became widespread. Fusion method Humans tend to see colours as contrasts between opponent

  8. Bird colour vision: behavioural thresholds reveal receptor noise.

    Science.gov (United States)

    Olsson, Peter; Lind, Olle; Kelber, Almut

    2015-01-15

    Birds have impressive physiological adaptations for colour vision, including tetrachromacy and coloured oil droplets, yet it is not clear exactly how well birds can discriminate the reflecting object colours that they encounter in nature. With behavioural experiments, we determined colour discrimination thresholds of chickens in bright and dim light. We performed the experiments with two colour series, orange and green, covering two parts of chicken colour space. These experiments allowed us to compare behavioural results with model expectations and determine how different noise types limit colour discrimination. At intensities ranging from bright light to those corresponding to early dusk (250-10 cd m(-2)), we describe thresholds accurately by assuming a constant signal-to-noise ratio, in agreement with an invariant Weber fraction of Weber's law. Below this intensity, signal-to-noise ratio decreases and Weber's law is violated because photon-shot noise limits colour discrimination. In very dim light (below 0.05 cd m(-2) for the orange series or 0.2 cd m(-2) for the green series) colour discrimination is possibly constrained by dark noise, and the lowest intensity at which chickens can discriminate colours is 0.025 and 0.08 cd m(-2) for the orange and green series, respectively. Our results suggest that chickens use spatial pooling of cone outputs to mitigate photon-shot noise. Surprisingly, we found no difference between colour discrimination of chickens and humans tested with the same test in bright light. © 2015. Published by The Company of Biologists Ltd.

  9. The Effect of Colour on Children's Cognitive Performance

    Science.gov (United States)

    Brooker, Alice; Franklin, Anna

    2016-01-01

    Background: The presence of red appears to hamper adults' cognitive performance relative to other colours (see Elliot & Maier, 2014, "Ann. Rev. Psychol." 65, 95). Aims and sample: Here, we investigate whether colour affects cognitive performance in 8- and 9-year-olds. Method: Children completed a battery of tasks once in the presence…

  10. Children's Models about Colours in Nahuatl-Speaking Communities

    Science.gov (United States)

    Gallegos-Cázares, Leticia; Flores-Camacho, Fernando; Calderón-Canales, Elena; Perrusquía-Máximo, Elvia; García-Rivera, Beatriz

    2014-01-01

    This paper presents the development and structure of indigenous children's ideas about mixing colours as well as their ideas about each colour, derived from their traditions. The children were interviewed both at school and outside it, and an educational proposal was implemented. Ideas expressed in the school context were analysed using the…

  11. Colour, pleasantness, and consumption behaviour within a meal

    NARCIS (Netherlands)

    Piqueras Fiszman, B.; Spence, C.

    2014-01-01

    It is often claimed that colour (e.g., in a meal) affects consumption behaviour. However, just how strong is the evidence in support of this claim, and what are the underlying mechanisms? It has been shown that not only the colour itself, but also the variety and the arrangement of the differently-c

  12. Colour Picking - the Pecking Order of Form and Function

    NARCIS (Netherlands)

    Nack, F.-M.; Manniesing, A.S.K.; Hardman, L.

    2003-01-01

    Multimedia presentation generation has to be able to balance the functional aspects of a presentation that address the information needs of the user and its aesthetic form. We demonstrate our approach using automatic colour design for which we integrate relevant aspects of colour theory. We do not p

  13. The absolute threshold of colour vision in the horse.

    Directory of Open Access Journals (Sweden)

    Lina S V Roth

    Full Text Available Arrhythmic mammals are active both during day and night if they are allowed. The arrhythmic horses are in possession of one of the largest terrestrial animal eyes and the purpose of this study is to reveal whether their eye is sensitive enough to see colours at night. During the day horses are known to have dichromatic colour vision. To disclose whether they can discriminate colours in dim light a behavioural dual choice experiment was performed. We started the training and testing at daylight intensities and the horses continued to choose correctly at a high frequency down to light intensities corresponding to moonlight. One Shetland pony mare, was able to discriminate colours at 0.08 cd/m(2, while a half blood gelding, still discriminated colours at 0.02 cd/m(2. For comparison, the colour vision limit for several human subjects tested in the very same experiment was also 0.02 cd/m(2. Hence, the threshold of colour vision for the horse that performed best was similar to that of the humans. The behavioural results are in line with calculations of the sensitivity of cone vision where the horse eye and human eye again are similar. The advantage of the large eye of the horse lies not in colour vision at night, but probably instead in achromatic tasks where presumably signal summation enhances sensitivity.

  14. Field-portable pixel super-resolution colour microscope.

    Science.gov (United States)

    Greenbaum, Alon; Akbari, Najva; Feizi, Alborz; Luo, Wei; Ozcan, Aydogan

    2013-01-01

    Based on partially-coherent digital in-line holography, we report a field-portable microscope that can render lensfree colour images over a wide field-of-view of e.g., >20 mm(2). This computational holographic microscope weighs less than 145 grams with dimensions smaller than 17×6×5 cm, making it especially suitable for field settings and point-of-care use. In this lensfree imaging design, we merged a colorization algorithm with a source shifting based multi-height pixel super-resolution technique to mitigate 'rainbow' like colour artefacts that are typical in holographic imaging. This image processing scheme is based on transforming the colour components of an RGB image into YUV colour space, which separates colour information from brightness component of an image. The resolution of our super-resolution colour microscope was characterized using a USAF test chart to confirm sub-micron spatial resolution, even for reconstructions that employ multi-height phase recovery to handle dense and connected objects. To further demonstrate the performance of this colour microscope Papanicolaou (Pap) smears were also successfully imaged. This field-portable and wide-field computational colour microscope could be useful for tele-medicine applications in resource poor settings.

  15. Luminous flux and colour maintenance investigation of integrated LED lamps

    DEFF Research Database (Denmark)

    Corell, Dennis Dan; Thorseth, Anders; Dam-Hansen, Carsten

    2014-01-01

    This article will present an investigation of the luminous flux and colour maintenance of white LED based retrofit lamps. The study includes 23 different types of integrated LED lamps, covering 18 directional and 5 non-directional. Luminous flux and colour data for operation up to 20000 h has been...

  16. Colour Metallography of Cast Iron Chapter 1 Introduction (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2009-01-01

    @@ 1.5 Colour metallography technique of cast iron Colour metallography possesses better differentiation ability and is more sensitive to segregation, grain orientation and stress state than black-white metallography. It adds functions to traditional metallography and displays wide application perspectives.

  17. Children's Models about Colours in Nahuatl-Speaking Communities

    Science.gov (United States)

    Gallegos-Cázares, Leticia; Flores-Camacho, Fernando; Calderón-Canales, Elena; Perrusquía-Máximo, Elvia; García-Rivera, Beatriz

    2014-01-01

    This paper presents the development and structure of indigenous children's ideas about mixing colours as well as their ideas about each colour, derived from their traditions. The children were interviewed both at school and outside it, and an educational proposal was implemented. Ideas expressed in the school context were analysed using the…

  18. Correlation between dichromatic colour vision and jumping performance in horses.

    Science.gov (United States)

    Spaas, Julie; Helsen, Werner F; Adriaenssens, Maurits; Broeckx, Sarah; Duchateau, Luc; Spaas, Jan H

    2014-10-01

    There is general agreement that horses have dichromatic colour vision with similar capabilities to human beings with red-green colour deficiencies. However, whether colour perception has an impact on equine jumping performance and how pronounced the colour stimulus might be for a horse is unknown. The present study investigated the relationship between the colour of the fences (blue or green) and the show jumping performance of 20 horses ridden by two riders using an indoor and outdoor set of green and blue fences. In the indoor arena, significantly more touches and faults were made on blue fences in comparison to green fences (median difference of 2.5 bars). When only touched bars were included, a significant median difference of one bar was found. Mares (n = 4) demonstrated more faults and had a significantly greater difference in touches and faults between the two colours than male horses (n = 16). Repeating the same experiment with eight horses in an outdoor grass arena revealed no significant differences between the two colours. In order to draw any definite conclusions, more research concerning the colour perception, influence of contrast with the arena surface and sex of horse is required.

  19. Colour gamuts in polychromatic dielectric elastomer artificial chromatophores

    Science.gov (United States)

    Rossiter, Jonathan; Conn, Andrew; Cerruto, Antonio; Winters, Amy; Roke, Calum

    2014-03-01

    Chromatophores are the colour changing organelles in the skins of animals including fish and cephalopods. The ability of cephalopods in particular to rapidly change their colouration in response to environmental changes, for example to camouflage against a new background, and in social situations, for example to attract a mate or repel a rival, is extremely attractive for engineering, medical, active clothing and biomimetic robotic applications. The rapid response of these chromatophores is possible by the direct coupling of fast acting muscle and pigmented saccules. In artificial chromatophores we are able to mimic this structure using electroactive polymer artificial muscles. In contrast to prior research which has demonstrated monochromatic artificial chromatophores, here we consider a novel multi-colour, multi-layer, artificial chromatophore structure inspired by the complex dermal chromatophore unit in nature and which exploits dielectric elastomer artificial muscles as the electroactive actuation mechanism. We investigate the optical properties of this chromatophore unit and explore the range of colours and effects that a single unit and a matrix of chromatophores can produce. The colour gamut of the multi-colour chromatophore is analysed and shows its suitability for practical display and camouflage applications. It is demonstrated how, by varying actuator strain and chromatophore base colour, the gamut can be shifted through colour space, thereby tuning the artificial chromatophore to a specific environment or application.

  20. Colour mimicry and sexual deception by Tongue orchids (Cryptostylis).

    Science.gov (United States)

    Gaskett, A C; Herberstein, M E

    2010-01-01

    Typically, floral colour attracts pollinators by advertising rewards such as nectar, but how does colour function when pollinators are deceived, unrewarded, and may even suffer fitness costs? Sexually deceptive orchids are pollinated only by male insects fooled into mating with orchid flowers and inadvertently transferring orchid pollinia. Over long distances, sexually deceptive orchids lure pollinators with counterfeit insect sex pheromones, but close-range deception with colour mimicry is a tantalising possibility. Here, for the first time, we analyse the colours of four sexually deceptive Cryptostylis orchid species and the female wasp they mimic (Lissopimpla excelsa, Ichneumonidae), from the perspective of the orchids' single, shared pollinator, male Lissopimpla excelsa. Despite appearing different to humans, the colours of the orchids and female wasps were effectively identical when mapped into a hymenopteran hexagonal colour space. The orchids and wasps reflected predominantly red-orange wavelengths, but UV was also reflected by raised bumps on two orchid species and by female wasp wings. The orchids' bright yellow pollinia contrasted significantly with their overall red colour. Orchid deception may therefore involve accurate and species-specific mimicry of wavelengths reflected by female wasps, and potentially, exploitation of insects' innate attraction to UV and yellow wavelengths. In general, mimicry may be facilitated by exploiting visual vulnerabilities and evolve more readily at the peripheries of sensory perception. Many sexually deceptive orchids are predominantly red, green or white: colours that are all potentially difficult for hymenoptera to detect or distinguish from the background.

  1. Colour mimicry and sexual deception by Tongue orchids ( Cryptostylis)

    Science.gov (United States)

    Gaskett, A. C.; Herberstein, M. E.

    2010-01-01

    Typically, floral colour attracts pollinators by advertising rewards such as nectar, but how does colour function when pollinators are deceived, unrewarded, and may even suffer fitness costs? Sexually deceptive orchids are pollinated only by male insects fooled into mating with orchid flowers and inadvertently transferring orchid pollinia. Over long distances, sexually deceptive orchids lure pollinators with counterfeit insect sex pheromones, but close-range deception with colour mimicry is a tantalising possibility. Here, for the first time, we analyse the colours of four sexually deceptive Cryptostylis orchid species and the female wasp they mimic ( Lissopimpla excelsa, Ichneumonidae), from the perspective of the orchids’ single, shared pollinator, male Lissopimpla excelsa. Despite appearing different to humans, the colours of the orchids and female wasps were effectively identical when mapped into a hymenopteran hexagonal colour space. The orchids and wasps reflected predominantly red-orange wavelengths, but UV was also reflected by raised bumps on two orchid species and by female wasp wings. The orchids’ bright yellow pollinia contrasted significantly with their overall red colour. Orchid deception may therefore involve accurate and species-specific mimicry of wavelengths reflected by female wasps, and potentially, exploitation of insects’ innate attraction to UV and yellow wavelengths. In general, mimicry may be facilitated by exploiting visual vulnerabilities and evolve more readily at the peripheries of sensory perception. Many sexually deceptive orchids are predominantly red, green or white: colours that are all potentially difficult for hymenoptera to detect or distinguish from the background.

  2. Temperature Effects on the Ash Colour of Forest Litter

    Directory of Open Access Journals (Sweden)

    Jolita Dūdaitė

    2011-12-01

    Full Text Available Abstract. Research was carried out to identify the influence of temperature (150, 250, 350, 450, 550ºC on the ash colour of Acer platanoides L. leaf litter and Pinus sylvestris L. needle litter samples collected from deciduous coniferous mixed forest in Lithuania (54º43‘ N 25º19‘ E in April 2010. To achieve the objective, a laboratory experiment was conducted to determine ash samples using the Munsell Colour Chart. The analysis of colours has demonstrated that considering all litter samples, an increase in the temperature of litter heating was found to increase ash colour values (r = 0.92; p = 0.01. All the samples (n = 50 of both litter species were divided into categories 2.5Y (5 samples, 7.5YR (10 samples and 10YR (35 samples. The total black Munsell colour was observed at a temperature of 350ºC for both litter species. Needle ash started turning bright at a temperature of 550ºC while the complete consumption of leaf litter was visible at a temperature of 450ºC. We conclude that the Munsell Colour Chart used for predicting the colour of ash is an informative feature to have the primary classification of ash. It is imperative to analyse the colour of the litter ash of the selected tree species in order to quickly and easily assess and predict their possible impact on the surrounding environment.

  3. Children's Models about Colours in Nahuatl-Speaking Communities

    Science.gov (United States)

    Gallegos-Cázares, Leticia; Flores-Camacho, Fernando; Calderón-Canales, Elena; Perrusquía-Máximo, Elvia; García-Rivera, Beatriz

    2014-10-01

    This paper presents the development and structure of indigenous children's ideas about mixing colours as well as their ideas about each colour, derived from their traditions. The children were interviewed both at school and outside it, and an educational proposal was implemented. Ideas expressed in the school context were analysed using the partial possible model, which states that the inferences and explanations used to describe a subject consist of constricting ideas, rules of correspondence, and a set of phenomenological inferences about processes. After identifying these components in the children's ideas, we developed models to describe their conceptions about mixing colours. We employed a different approach to analyse children's ideas related to their cultural context. The results showed that children change from a conception that focuses on colours as entities that do not change and as properties of objects (model 1) to the idea that colour represents a quality of substances or objects that can be modified by mixing colours (model 2). Cultural context analysis showed that stories are independent from one another and that they are not connected to colour mixing processes, only to the actions of colour on people. We concluded that students generate independent constructions between school and cultural knowledge.

  4. Colour measurements of surfaces to evaluate the restoration materials

    Science.gov (United States)

    Lo Monaco, Angela; Marabelli, Maurizio; Pelosi, Claudia; Picchio, Rodolfo

    2011-06-01

    In this paper two case studies on the application of colour measurements for the evaluation of some restoration materials are discussed. The materials related to the research are: watercolours employed in restoration of wall paintings and preservative/consolidants for wood artifacts. Commercial watercolours, supplied by Maimeri, Windsor&Newton and Talens factories have been tested. Colour measurements have been performed by means of a reflectance spectrophotometer (RS) before and after accelerated ageing of watercolours at 92% relative humidity (RH) and in a Solar Box chamber. The experimental results show that watercolours based on natural earths and artificial ultramarine undergo the main colour changes, expressed as L*, a* and b* variations and total colour difference (▵E*). In the other cases colour differences depend on both watercolour typology and suppliers. The other example concerns the evaluation of colour change due to surface treatment of Poplar (Populus sp.) and chestnut (Castanea sativa L.) wood samples. The wooden samples have been treated with a novel organic preservative/consolidant product that has been tested also in a real case as comparison. The treated samples have been artificially aged in Solar Box chamber equipped with a 280 nm UV filter. Colour has been measured before and after the artificial ageing by means of a RS. Colour changes have been determined also for the main door of an historical mansion in Viterbo, made of chestnut wood, and exposed outdoors.

  5. Structures and colour properties of new red wine pigments

    DEFF Research Database (Denmark)

    Håkansson, Anders Eckart; Pardon, K.; Hayasaka, Y.

    2003-01-01

    the colour properties of the pigments were characterized; it could be demonstrated that the pyranoanthocyanins retained their red colour at pH 3.6 in model wine and were resistant to bisulfite-mediated bleaching. Finally, HPLC-MS analysis confirmed the presence of both anthocyanin-derived pigments in red...... wine....

  6. Field-portable pixel super-resolution colour microscope.

    Directory of Open Access Journals (Sweden)

    Alon Greenbaum

    Full Text Available Based on partially-coherent digital in-line holography, we report a field-portable microscope that can render lensfree colour images over a wide field-of-view of e.g., >20 mm(2. This computational holographic microscope weighs less than 145 grams with dimensions smaller than 17×6×5 cm, making it especially suitable for field settings and point-of-care use. In this lensfree imaging design, we merged a colorization algorithm with a source shifting based multi-height pixel super-resolution technique to mitigate 'rainbow' like colour artefacts that are typical in holographic imaging. This image processing scheme is based on transforming the colour components of an RGB image into YUV colour space, which separates colour information from brightness component of an image. The resolution of our super-resolution colour microscope was characterized using a USAF test chart to confirm sub-micron spatial resolution, even for reconstructions that employ multi-height phase recovery to handle dense and connected objects. To further demonstrate the performance of this colour microscope Papanicolaou (Pap smears were also successfully imaged. This field-portable and wide-field computational colour microscope could be useful for tele-medicine applications in resource poor settings.

  7. Optical and Colour Stability of Graphic Paperboards and Prints

    Directory of Open Access Journals (Sweden)

    Marjeta Cernic Letnar

    2003-04-01

    Full Text Available In the study we investigated the influence of surface treatment on permanence and stability of various graphic paperboard types - board for books, brochures, business cards, calendars, protection package - under the conditions of accelerated ageing with increased temperature and relative humidity in the absence of light according to ISO/5630/3, and as specified for material on paper/board of permanent value by EN/ISO 9706 (8. Paperboards were coated with various coating colours, and subsequently lab printed in offset technique. The effect of artificial ageing on surface properties as well as on image optical and colour stability was monitored.The changes observed in surface characteristics such as smoothness, roughness, air permeability, absorptivity before and after the accelerated ageing process revealed a strong influence of coating components (pigments, binders and surface treatment type. Increase in roughness, alteration of board absorption behaviour and change in optical and colour parameters - decrease in brightness, increase in yellowness, colour shift with samples containing higher amount of optical brightening agents - were the most pronounced results.Measured differences in printing colour (dE and optical density values indicated that colour stability of offset image approached the limit values, which are set for an image of still acceptable quality. Black (K exhibited the highest stability among CMYK colours. Image colour stability significantly depends on surface and optical board characteristics, especially on gloss and optical brightener agent, as well as on board fibre composition and coating pigments.

  8. Spray coating of superhydrophobic and angle-independent coloured films.

    Science.gov (United States)

    Ge, Dengteng; Yang, Lili; Wu, Gaoxiang; Yang, Shu

    2014-03-07

    Angle-independent coloured films with superhydrophobicity were fabricated from quasi-amorphous arrays of monodispersed fluorinated silica nanoparticles via one-step spray coating. The film exhibited a high contact angle (>150°) and a low roll-off angle (~2°) and the colour could be tuned to blue, green and moccasin by varying the size of the nanoparticles.

  9. Counting with Colours? Effect of Colours on the Numerical Abilities of House Crows (Corvus splendens) and Common Myna (Acridotheres tristis)

    Science.gov (United States)

    Rahman, Nor Amira Abdul; Ali, Zalila; Zuharah, Wan Fatma; Fadzly, Nik

    2016-01-01

    We conducted several aviary experiments to investigate the influence of colours in quantity judgments of two species of birds; house crow (Corvus splendens) and common myna (Acridotheres tristis). Different quantity (in seven different food proportions) of mealworms were presented nonsequentially to all birds using artificially coloured red mealworms, for experiment 1, and using artificially coloured green mealworms, for experiment 2. Both red and green coloured mealworms have no significant effect on house crow’s quantity judgments (red: ANOVA: F6,30 = 1.748, p = 0.144; and green: ANOVA: F6,30= 1.085, p = 0.394). Common myna, however, showed a strong influence of red colour in their quantity judgment (ANOVA: F6,30 = 2.922, p = 0.023) as they succeeded in choosing the largest amount of food between two cups, but not when offered food using green coloured mealworms (ANOVA: F6,30 = 1.183, p = 0.342). In the next experiment, we hypothesised that both house crow and common myna will prefer red coloured food items over green coloured food items, when factors such as the amount of food is equal. We chose to test red and green colours because both colours play an important role in most avian food selections. Results showed that there were no significant differences in the selection of red or green coloured mealworms for both house crows (ANOVA: F6,30 = 2.310, p = 0.06) and common myna (ANOVA: F6,30 = 0.823, p = 0.561). PMID:27688847

  10. Galaxy Zoo: the independence of morphology and colour

    CERN Document Server

    Bamford, Steven P; Baldry, Ivan K; Land, Kate; Lintott, Chris J; Schawinski, Kevin; Slosar, Anze; Szalay, Alexander S; Thomas, Daniel; Torki, Mehri; Andreescu, Dan; Edmondson, Edward M; Miller, Christopher J; Murray, Phil; Raddick, M Jordan; Vandenberg, Jan

    2008-01-01

    We analyse the relationships between galaxy morphology, colour, environment and stellar mass using data for 130352 objects from Galaxy Zoo. The majority of the morphology-density relation is driven by variation in morphological fraction with environment at fixed stellar mass, rather than by the environmental dependence of the stellar mass function. We conclusively show that the colour and morphology bimodalities are largely independent functions of environment. Galaxies with high stellar masses are mostly red, in all environments. Low stellar-mass galaxies are mostly blue in low-density environments and mostly red in high-density environments. While galaxies with early-type morphology do always have higher red fractions, this is sub-dominant compared to the dependence of red fraction on stellar mass and environment. Only a small part of the colour-density relation thus results from the morphology-density relation. The colour-density relation is primarily driven by variations in colour fractions at fixed morph...

  11. There's more to taste in a coloured bowl.

    Science.gov (United States)

    Harrar, Vanessa; Piqueras-Fiszman, Betina; Spence, Charles

    2011-01-01

    The flavour and pleasantness of food and drinks are affected by their colour, their texture or crunch, and even by the shape and weight of the plate or glass. But, can the colour of the bowl also affect the taste of the food it contains? To answer this question we served popcorn in four different coloured bowls, and participants rated sweetness, saltiness, and overall liking. The sweet popcorn, in addition to being sweet, was perceived as saltier when eaten out of a coloured (as compared to a white) bowl, and vice versa for the salty popcorn. These results demonstrate that colour in bowl design can be used to elicit perceptions of sweetness and saltiness in real foods.

  12. Implementation and characterization of a fibre-optic colour sensor

    Science.gov (United States)

    Bajić, Jovan S.; Stupar, Dragan Z.; Dakić, Bojan M.; Manojlović, Lazo M.; Slankamenac, Miloš P.; Živanov, Miloš B.

    2014-09-01

    In this paper the implementation of a fibre-optic sensor for colour detection based on reflective colour sensing is proposed. The sensor consists of three plastic optical fibres emitting red, green and blue components and one optical fibre collecting light reflected from the object. Red, green and blue LEDs are excited at different frequencies. In this way detection of the reflected signal is achieved with only one photodetector and three bandpass filters. Bandpass filters are implemented as digital IIR (infinite impulse response) filters on the microcontroller. Results obtained from the proposed sensor are compared with commercial available colour sensors and the results are satisfactory. Analyses of the sensor performance both in RGB and HSV colour space are done. The proposed solution shows that in specific applications by using the HSV model the sensor can be used both as a colour and distance sensor.

  13. Recent advances in the biomimicry of structural colours.

    Science.gov (United States)

    Dumanli, Ahu Gümrah; Savin, Thierry

    2016-12-21

    Nature has mastered the construction of nanostructures with well-defined macroscopic effects and purposes. Structural colouration is a visible consequence of the particular patterning of a reflecting surface with regular structures at submicron length scales. Structural colours usually appear bright, shiny, iridescent or with a metallic look, as a result of physical processes such as diffraction, interference, or scattering with a typically small dissipative loss. These features have recently attracted much research effort in materials science, chemistry, engineering and physics, in order to understand and produce structural colours. In these early stages of photonics, researchers facing an infinite array of possible colour-producing structures are heavily inspired by the elaborate architectures they find in nature. We review here the recent technological strategies employed to artificially mimic the structural colours found in nature, as well as some of their current and potential applications.

  14. “The primary colour of delight”

    DEFF Research Database (Denmark)

    Østermark-Johansen, Lene

    2016-01-01

    threads of Venetian painting relate in a complex manner to J.A.M. Whistler’s controversial Nocturne in Black and Gold: The Falling Rocket and to the influence of Byzantine art on Venetian painting. Gold figures as mass, as line, as surface covering, as composite sculptural material, as an intriguing...... reference to the material reflects a range of highly topical late Victorian issues, whether the latest archaeological discoveries, the latest art controversies or the late Victorian interest in myth. Pater’s golden writings, themselves distilled through endless revision and polishing, thus serve...... with the polychrome sculpture of Antiquity and spoke of Homer’s language as “chryselefantine”. He thus addressed the controversial issue of colour in ancient sculpture, while linking sculpture and language by means of the adjective “chryselefantine”. In his novel Marius the Epicurean (1885) Apuleius’ The Golden Ass...

  15. Micro-Raman analysis of coloured lithographs.

    Science.gov (United States)

    Castro, K; Vandenabeele, P; Rodríguez-Laso, M D; Moens, L; Madariaga, J M

    2004-06-01

    Raman micro-spectroscopy was chosen for analysis and identification of the pigments present in four nineteenth-century hand-coloured lithographs, as this technique has several advantages over others for this purpose. The possibility of performing completely non-destructive analysis without any sampling is probably one of its most favourable qualities for art analysis. Raman spectroscopy can also be used to determine some pigments that cannot be detected using FTIR, such as vermilion, carbon blacks, cadmium pigments, etc. Among others, Prussian blue, ultramarine blue, carbon black, chrome yellow, yellow ochre, red lead, red iron oxide, burnt Sienna, indigo blue, chrome orange, phthalocyanine green, and some other organic pigments, were determined in the specimens. The results obtained have led to doubts about the age of the lithographs.

  16. Mouse Simulation Using Two Coloured Tapes

    CERN Document Server

    Kumar, Vikram; Mahe, Swapnil; Vyawahare, Swapnil; 10.5121/ijist.2012.2206

    2012-01-01

    In this paper, we present a novel approach for Human Computer Interaction (HCI) where, we control cursor movement using a real-time camera. Current methods involve changing mouse parts such as adding more buttons or changing the position of the tracking ball. Instead, our method is to use a camera and computer vision technology, such as image segmentation and gesture recognition, to control mouse tasks (left and right clicking, double-clicking, and scrolling) and we show how it can perform everything as current mouse devices can. The software will be developed in JAVA language. Recognition and pose estimation in this system are user independent and robust as we will be using colour tapes on our finger to perform actions. The software can be used as an intuitive input interface to applications that require multi-dimensional control e.g. computer games etc.

  17. “The primary colour of delight”

    DEFF Research Database (Denmark)

    Østermark-Johansen, Lene

    2016-01-01

    The Irish poet William Sharp recalled visiting Walter Pater’s college rooms, when a golden ray of sunlight suddenly provoked a lengthy discourse on gold from the Victorian critic. Pater explored what he called “the primary colour of delight” throughout his thirty years as a writer. This paper maps...... the range of Pater’s use of gold in his writings in an attempt to capture the complexities of his notion of the purest of metals. In his Greek essays Pater dealt with the purest gold as a material for sculpture as it had recently surfaced in Heinrich Schliemann’s excavations of Mycenae. But he also dealt...... threads of Venetian painting relate in a complex manner to J.A.M. Whistler’s controversial Nocturne in Black and Gold: The Falling Rocket and to the influence of Byzantine art on Venetian painting. Gold figures as mass, as line, as surface covering, as composite sculptural material, as an intriguing...

  18. Quarkonium suppression: Gluonic dissociation vs. colour screening

    Indian Academy of Sciences (India)

    Binoy Krishna Patra; Dinesh Kumar Srivastava

    2003-05-01

    We evaluate the suppression of / production in an equilibrating quark gluon plasma for two competing mechanisms: Debye screening of colour interaction and dissociation due to energetic gluons. Results are obtained for S + S and Au + Au collisions at RHIC and LHC energies. At RHIC energies the gluonic dissociation of the charmonium is found to be equally important for both the systems while the screening of the interaction plays a significant role only for the larger systems. At LHC energies the Debye mechanism is found to dominate both the systems. While considering the suppression of directly produced $\\Upsilon$ at LHC energies, we find that only the gluonic dissociation mechanism comes into play for the initial conditions taken from the self screened parton cascade model in these studies.

  19. PUNGENT AND COLOUR COMPOUNDS OF RED PEPPERS

    Directory of Open Access Journals (Sweden)

    Çetin KADAKAL

    2001-03-01

    Full Text Available The capcaicinoid amount of red peppers from Solanacea family is used for the evaluation of quality and classification in many countries. Capsaicin is the major pungent principle (69 % of capsaicinoids. The others are dihidrocapsaicin (22 %, nordihidrocapsaicin (7 %, homocapsaicin (1 % and homodihidrocapsaicin (1 %. As in most foods, the carotenoids of red peppers are also important compounds. Carotenoids are typical colour pigments and some of them have vitamin A activity. Major carotenoids of ripe fruit of red peppers are capsanthin, capsorubin, ß-carotene and zeaxanthin. Capcaicinoid and carotenoid contents of red peppers grown in many different regions of the world, their properties and roles on the human health were given in this review.

  20. The role of meaning in grapheme-colour synaesthesia.

    Science.gov (United States)

    Dixon, Mike J; Smilek, Daniel; Duffy, Patricia L; Zanna, Mark P; Merikle, Philip M

    2006-02-01

    When the synaesthete, J, is shown black graphemes, in addition to perceiving the black digits or letters she also experiences highly specific colours that overlay the graphemes (e.g., 5 is pink, S is green). We used ambiguous graphemes in a Stroop-type task to show that the exact same forms (e.g., 5) can elicit different synaesthetic colours depending on whether they are interpreted as digits or letters. J was shown strings of black digits (e.g., 3 4 5 6 7) or words (e.g., M U S I C for 1 sec. All but one of the graphemes then disappeared and the remaining grapheme changed to a colour that J had to name as quickly as possible. The key trials involved coloured graphemes that were ambiguous (e.g., the 5 in the strings above could be interpreted either as a digit or as a letter). On congruent trials, the colour of the ambiguous target grapheme was the same as J's photism for the digit or letter interpretations of the grapheme. On incongruent trials, the colours of the ambiguous target graphemes were different than the colours of J's photisms for the digit or letter interpretations of the graphemes. On digit-context incongruent trials, the ambiguous graphemes were presented in J's colour for the letter-interpretations of the graphemes, whereas on letter-context incongruent trials, the ambiguous graphemes were presented in J's colours for the digit-interpretations of the graphemes. Thus the same ambiguous grapheme (e.g., a pink 5) served as a congruent stimulus in one context and an incongruent stimulus in another context. J's response times showed that ambiguous graphemes elicited different photisms depending on whether they were interpreted as digits or letters. This finding suggests that it is not the form but the meaning of graphemes (whether they are interpreted as digits or letters) that determines the colours of synaesthetic photisms.

  1. Shaping communicative colour signals over evolutionary time

    Science.gov (United States)

    Oyola Morales, José R.; Vital-García, Cuauhcihuatl; Hews, Diana K.; Martins, Emília P.

    2016-01-01

    Many evolutionary forces can shape the evolution of communicative signals, and the long-term impact of each force may depend on relative timing and magnitude. We use a phylogenetic analysis to infer the history of blue belly patches of Sceloporus lizards, and a detailed spectrophotometric analysis of four species to explore the specific forces shaping evolutionary change. We find that the ancestor of Sceloporus had blue patches. We then focus on four species; the first evolutionary shift (captured by comparison of S. merriami and S. siniferus) represents an ancient loss of the belly patch by S. siniferus, and the second evolutionary shift, bounded by S. undulatus and S. virgatus, represents a more recent loss of blue belly patch by S. virgatus. Conspicuousness measurements suggest that the species with the recent loss (S. virgatus) is the least conspicuous. Results for two other species (S. siniferus and S. merriami) suggest that over longer periods of evolutionary time, new signal colours have arisen which minimize absolute contrast with the habitat while maximizing conspicuousness to a lizard receiver. Specifically, males of the species representing an ancient loss of blue patch (S. siniferus) are more conspicuous than are females in the UV, whereas S. merriami males have evolved a green element that makes their belly patches highly sexually dimorphic but no more conspicuous than the white bellies of S. merriami females. Thus, our results suggest that natural selection may act more immediately to reduce conspicuousness, whereas sexual selection may have a more complex impact on communicative signals through the introduction of new colours. PMID:28018661

  2. Spectrophotometric Evaluation of Colour Stability of Nano Hybrid Composite Resin in Commonly Used Food Colourants in Asian Countries

    Science.gov (United States)

    Sajjan, Girija S; Varma Kanumuri, Madhu

    2017-01-01

    Introduction There is growing interest in colour stability of aesthetic restorations. So far few studies have been reported. Aim This study was designed to investigate the effects of different common food colourants i.e., Turmeric and Carmoisine (orange red dye) consumed by patients in Asian countries on a recent nano hybrid composite resin. Materials and Methods A total of sixty disk shaped specimens measuring 10 mm in diameter and 2 mm in thickness were prepared. The samples were divided into two groups {Z 100 (Dental restorative composite) Filtek Z 250 XT (Nano hybrid universal restorative)}. Baseline colour measurement of all specimens were made using reflectance spectrophotometer with CIE L*a*b* system. Specimens were immersed in artificial saliva and different experimental solutions containing food colourants (carmoisine solution and turmeric solution) for three hours per day at 37°C. Colour measurements were made after 15 days. Colour difference (ΔE*) was calculated. Mean values were compared by one-way analysis of variance (ANOVA). Multiple range test by Tukey Post-hoc test procedure was employed to identify the significant groups at 5% level. Results Z 100 showed minimum staining capacity when compared to Z 250 XT in both the colourant solutions. Conclusion The nanohybrid composite resin containing TEGDMA showed significant colour change when compared to that of microhybrid composite resin as a result of staining in turmeric and carmoisine solution. PMID:28274047

  3. Dynamic miniature lighting system with low correlated colour temperature and high colour rendering index for museum lighting of fragile artefacts

    DEFF Research Database (Denmark)

    Thorseth, Anders; Corell, Dennis Dan; Poulsen, Peter Behrensdorff

    2013-01-01

    Illumination of fragile and irreplaceable historical objects exhibited to the public presents challenges with regards to: good colour rendering, low photochemical degradation of sensitive materials and general energy consumption. We present a dynamic tri-colour LED lighting system for illumination...... of historical artefacts in display cases at museums and other exhibitions, which can replace 3-5 Watt incandescent light bulbs with a correlated colour temperature (CCT) from 2000 K to 2400 K. The solution decreases the energy consumption by up to 80 %, while maintaining colour rendering indices (Ra) above 90...... and important special colour rendering indices R9 between 50 and 90, while decreasing the level of harmful short wavelength radiation by between 20 - 30 %....

  4. Colour preferences of UK garden birds at supplementary seed feeders.

    Science.gov (United States)

    Rothery, Luke; Scott, Graham W; Morrell, Lesley J

    2017-01-01

    Supplementary feeding of garden birds generally has benefits for both bird populations and human wellbeing. Birds have excellent colour vision, and show preferences for food items of particular colours, but research into colour preferences associated with artificial feeders is limited to hummingbirds. Here, we investigated the colour preferences of common UK garden birds foraging at seed-dispensing artificial feeders containing identical food. We presented birds simultaneously with an array of eight differently coloured feeders, and recorded the number of visits made to each colour over 370 30-minute observation periods in the winter of 2014/15. In addition, we surveyed visitors to a garden centre and science festival to determine the colour preferences of likely purchasers of seed feeders. Our results suggest that silver and green feeders were visited by higher numbers of individuals of several common garden bird species, while red and yellow feeders received fewer visits. In contrast, people preferred red, yellow, blue and green feeders. We suggest that green feeders may be simultaneously marketable and attractive to foraging birds.

  5. A developmental study of the acquisition of Russian colour terms.

    Science.gov (United States)

    Davies, I R; Corbett, G G; McGurk, H; MacDermid, C

    1998-06-01

    We report a study of the acquisition of colour terms by Russian children which had two main aims: first, to test Berlin & Kay's (1969) theory of colour universals using acquisition order as a measure of basicness; and secondly, to see if the two BLUE terms of Russian are genuinely basic. Two hundred children aged from three to six-years-old were tested on three colour-tasks--colour term listing, colour term production and colour term comprehension. To a reasonable approximation, the order of colour term acquisition was in accord with Berlin & Kay's theory, but the data are also consistent with the weaker claim that primary terms tend to be learned before derived terms. On balance the data were consistent with Russian exceptionally, having an extra term for the BLUE region. But, the two BLUE terms--goluboj 'light blue' and sinij 'dark blue'--were confused more often than other pairs of terms even by the five- to six-year-old sample.

  6. Kac’s ring: The case of four colours

    Indian Academy of Sciences (India)

    MANAN JAIN

    2017-04-01

    We present an instance from nonequilibrium statistical mechanics which combines increase in entropy and finite Poincaré recurrence time. The model we consider is a variation of the well-known Kac’s ring where we consider balls of four colours. As is known, Kac introduced this model where balls arranged between lattice sites, in each time step, move one step clockwise. The colour of the balls change as they cross marked sites. This very simple example rationalize the increase in entropy and recurrence. In our variation, the interesting quantity which counts the difference in the number of balls of different colours is shown to reduce to a set of linear equations if the probability of change of colour is symmetric among a pair of colours. The transfer matrix turns out to be non-Hermitian with real eigenvalues, leading to all colours being equally likely for long times, and a monotonically varying entropy. The new features appearing due to four colours is very instructive.

  7. Why background colour matters to bees and flowers.

    Science.gov (United States)

    Bukovac, Zoë; Shrestha, Mani; Garcia, Jair E; Burd, Martin; Dorin, Alan; Dyer, Adrian G

    2017-05-01

    Flowers are often viewed by bee pollinators against a variety of different backgrounds. On the Australian continent, backgrounds are very diverse and include surface examples of all major geological stages of the Earth's history, which have been present during the entire evolutionary period of Angiosperms. Flower signals in Australia are also representative of typical worldwide evolutionary spectral adaptations that enable successful pollination. We measured the spectral properties of 581 natural surfaces, including rocks, sand, green leaves, and dry plant materials, sampled from tropical Cairns through to the southern tip of mainland Australia. We modelled in a hexagon colour space, how interactions between background spectra and flower-like colour stimuli affect reliable discrimination and detection in bee pollinators. We calculated the extent to which a given locus would be conflated with the loci of a different flower-colour stimulus using empirically determined colour discrimination regions for bee vision. Our results reveal that whilst colour signals are robust in homogeneous background viewing conditions, there could be significant pressure on plant flowers to evolve saliently-different colours to overcome background spectral noise. We thus show that perceptual noise has a large influence on how colour information can be used in natural conditions.

  8. Influence of Texture and Colour in Breast TMA Classification

    Science.gov (United States)

    Fernández-Carrobles, M. Milagro; Bueno, Gloria; Déniz, Oscar; Salido, Jesús; García-Rojo, Marcial; González-López, Lucía

    2015-01-01

    Breast cancer diagnosis is still done by observation of biopsies under the microscope. The development of automated methods for breast TMA classification would reduce diagnostic time. This paper is a step towards the solution for this problem and shows a complete study of breast TMA classification based on colour models and texture descriptors. The TMA images were divided into four classes: i) benign stromal tissue with cellularity, ii) adipose tissue, iii) benign and benign anomalous structures, and iv) ductal and lobular carcinomas. A relevant set of features was obtained on eight different colour models from first and second order Haralick statistical descriptors obtained from the intensity image, Fourier, Wavelets, Multiresolution Gabor, M-LBP and textons descriptors. Furthermore, four types of classification experiments were performed using six different classifiers: (1) classification per colour model individually, (2) classification by combination of colour models, (3) classification by combination of colour models and descriptors, and (4) classification by combination of colour models and descriptors with a previous feature set reduction. The best result shows an average of 99.05% accuracy and 98.34% positive predictive value. These results have been obtained by means of a bagging tree classifier with combination of six colour models and the use of 1719 non-correlated (correlation threshold of 97%) textural features based on Statistical, M-LBP, Gabor and Spatial textons descriptors. PMID:26513238

  9. Dynamic Colour Possibilities and Functional Properties of Thermochromic Printing Inks

    Directory of Open Access Journals (Sweden)

    Rahela Kulcar

    2012-07-01

    Full Text Available Thermochromic printing inks change their colour regarding the change in temperature and they are one of the major groups of colour-changing inks. One of the most frequently used thermochromic material in printing inks are leuco dyes. The colour of thermochromic prints is dynamic, it is not just temperature-dependent, but it also depends on thermal history. The effect is described by colour hysteresis. This paper aims at discussing general aspects of thermochromic inks, dynamic colorimetric properties of leuco dye-based thermochromic inks, their stability and principle of variable-temperature colour measurement. Thermochromic material is protected in round-shaped capsules. They are much larger than pigments in conventional inks. The polymer envelopes of pigment capsules are more stable against oxidation than the binder. If these envelopes are damaged, the dynamic colour is irreversibly lost. Our aim is to analyse the colorimetric properties of several reversible screen-printed UV-curing leuco dye thermochromic inks with different activation temperatures printed on paper. A small analysis of irreversible thermochromic inks will be presented for comparison with reversible thermochromic inks. Moreover, so as to show interesting possibilities, a combination of different inks was made, an irreversible thermochromic ink was printed on top of the red and blue reversible thermochromic inks. Special attention was given to the characterization of colour hysteresis and the meaning of activation temperature.

  10. Colour preferences of UK garden birds at supplementary seed feeders

    Science.gov (United States)

    Rothery, Luke; Scott, Graham W.

    2017-01-01

    Supplementary feeding of garden birds generally has benefits for both bird populations and human wellbeing. Birds have excellent colour vision, and show preferences for food items of particular colours, but research into colour preferences associated with artificial feeders is limited to hummingbirds. Here, we investigated the colour preferences of common UK garden birds foraging at seed-dispensing artificial feeders containing identical food. We presented birds simultaneously with an array of eight differently coloured feeders, and recorded the number of visits made to each colour over 370 30-minute observation periods in the winter of 2014/15. In addition, we surveyed visitors to a garden centre and science festival to determine the colour preferences of likely purchasers of seed feeders. Our results suggest that silver and green feeders were visited by higher numbers of individuals of several common garden bird species, while red and yellow feeders received fewer visits. In contrast, people preferred red, yellow, blue and green feeders. We suggest that green feeders may be simultaneously marketable and attractive to foraging birds. PMID:28212435

  11. Colour changes by laser irradiation of reddish building limestones

    Science.gov (United States)

    Grossi, C. M.; Benavente, D.

    2016-10-01

    We have used X-ray photoelectron spectroscopy (XPS) as a novel method to investigate the causes of colour changes in a reddish limestone under irradiation by a Q-switched Nd:YAG 1064 nm laser. We irradiated clean dry and wet surfaces of Pidramuelle Roja, a building stone frequently used in the Asturian heritage, at fluences ranging from 0.12 to 1.47 J cm-2. We measured the colour coordinates and undertook XPS analysis of the state of oxidation of iron both before and after irradiation. Visible colour changes and potential aesthetic damage occurred on dry surfaces from a fluence of 0.31 J cm-2, with the stone showing a greening effect and very intense darkening. The colour change on dry surfaces was considerably higher than on wet surfaces, which at the highest fluence (1.47 J cm-2) was also above the human visual detection threshold. The use of XPS demonstrated that the change in colour (chroma and hue) is associated with a reduction in the iron oxidation state on dry surfaces during laser irradiation. This points out to a potential routinary use of XPS to analyse causes of colour changes during laser cleaning in other types of coloured building stones.

  12. Colour constancy across the life span: evidence for compensatory mechanisms.

    Science.gov (United States)

    Wuerger, Sophie

    2013-01-01

    It is well known that the peripheral visual system declines with age: the yellowing of the lens causes a selective reduction of short-wavelength light and sensitivity losses occur in the cone receptor mechanisms. At the same time, our subjective experience of colour does not change with age. The main purpose of this large-scale study (n = 185) covering a wide age range of colour-normal observers (18-75 years of age) was to assess the extent to which the human visual system is able to compensate for the changes in the optical media and at which level of processing this compensation is likely to occur. We report two main results: (1) Supra-threshold parafoveal colour perception remains largely unaffected by the age-related changes in the optical media (yellowing of the lens) whereas our ability to discriminate between small colour differences is compromised with an increase in age. (2) Significant changes in colour appearance are only found for unique green settings under daylight viewing condition which is consistent with the idea that the yellow-blue mechanism is most affected by an increase in age due to selective attenuation of short-wavelength light. The data on the invariance of hue perception, in conjunction with the age-related decline in chromatic sensitivity, provides evidence for compensatory mechanisms that enable colour-normal human observers a large degree of colour constancy across the life span. These compensatory mechanisms are likely to originate at cortical sites.

  13. Influence of Texture and Colour in Breast TMA Classification.

    Science.gov (United States)

    Fernández-Carrobles, M Milagro; Bueno, Gloria; Déniz, Oscar; Salido, Jesús; García-Rojo, Marcial; González-López, Lucía

    2015-01-01

    Breast cancer diagnosis is still done by observation of biopsies under the microscope. The development of automated methods for breast TMA classification would reduce diagnostic time. This paper is a step towards the solution for this problem and shows a complete study of breast TMA classification based on colour models and texture descriptors. The TMA images were divided into four classes: i) benign stromal tissue with cellularity, ii) adipose tissue, iii) benign and benign anomalous structures, and iv) ductal and lobular carcinomas. A relevant set of features was obtained on eight different colour models from first and second order Haralick statistical descriptors obtained from the intensity image, Fourier, Wavelets, Multiresolution Gabor, M-LBP and textons descriptors. Furthermore, four types of classification experiments were performed using six different classifiers: (1) classification per colour model individually, (2) classification by combination of colour models, (3) classification by combination of colour models and descriptors, and (4) classification by combination of colour models and descriptors with a previous feature set reduction. The best result shows an average of 99.05% accuracy and 98.34% positive predictive value. These results have been obtained by means of a bagging tree classifier with combination of six colour models and the use of 1719 non-correlated (correlation threshold of 97%) textural features based on Statistical, M-LBP, Gabor and Spatial textons descriptors.

  14. Opening up a Colourful Cosmic Jewel Box

    Science.gov (United States)

    2009-10-01

    The combination of images taken by three exceptional telescopes, the ESO Very Large Telescope on Cerro Paranal , the MPG/ESO 2.2-metre telescope at ESO's La Silla observatory and the NASA/ESA Hubble Space Telescope, has allowed the stunning Jewel Box star cluster to be seen in a whole new light. Star clusters are among the most visually alluring and astrophysically fascinating objects in the sky. One of the most spectacular nestles deep in the southern skies near the Southern Cross in the constellation of Crux. The Kappa Crucis Cluster, also known as NGC 4755 or simply the "Jewel Box" is just bright enough to be seen with the unaided eye. It was given its nickname by the English astronomer John Herschel in the 1830s because the striking colour contrasts of its pale blue and orange stars seen through a telescope reminded Herschel of a piece of exotic jewellery. Open clusters [1] such as NGC 4755 typically contain anything from a few to thousands of stars that are loosely bound together by gravity. Because the stars all formed together from the same cloud of gas and dust their ages and chemical makeup are similar, which makes them ideal laboratories for studying how stars evolve. The position of the cluster amongst the rich star fields and dust clouds of the southern Milky Way is shown in the very wide field view generated from the Digitized Sky Survey 2 data. This image also includes one of the stars of the Southern Cross as well as part of the huge dark cloud of the Coal Sack [2]. A new image taken with the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile shows the cluster and its rich surroundings in all their multicoloured glory. The large field of view of the WFI shows a vast number of stars. Many are located behind the dusty clouds of the Milky Way and therefore appear red [3]. The FORS1 instrument on the ESO Very Large Telescope (VLT) allows a much closer look at the cluster itself. The telescope's huge mirror

  15. The Impact of Effective Colour Management for Textile Coloration: An Instrumental Way Towards Perfection

    Directory of Open Access Journals (Sweden)

    Zeeshan Khatri

    2011-10-01

    Full Text Available The colour produced by the application of either dyes or pigments on textiles must be close matched with reference (standard provided by buyer. Meeting stringent requirement from Buyer that demands right colour on right time is not a simple task to achieve. The process of colour matching is a lengthy process and needs many trials to get close match. The colour quantification through instruments helps to cut most of the lead time, however, there is a serious need to manage colour during colour approval stage and coloration process. We adopted four different routes for colour approval and compared with the conventional one. The study revealed that out of four instrumental options, the 4th option had shortest route and minimum lead time. We also concluded that by using spectrophotometer, K/S (Colour Strength and colorimetic values are very good to not only communicate colour numerically but also controlling colour during colour approval process.

  16. THE ICONOGRAPHIC COLOUR SYMBOLISM IN BIBLICAL POEMS BY SERGEI YESENIN

    Directory of Open Access Journals (Sweden)

    Natalia Vladimirovna Mikhalenko

    2014-11-01

    Full Text Available The Biblical poems by Sergei Yesenin are full of pathos of theurgic reforms and creation of a new world. All components of these poems (images, spatial-temporal organization, colour symbolics stressed the importance of ongoing changes. The colours in small poems not only correspond to normal natural colours, but also bear a symbolic meaning, drawing the reader to the iconographic mysticism. The colourful preferences correspond to the tradition (of the Old or New Testaments, iconography or liturgy, as well as scenic tradition, which Yesenin follows in his poetry. Creating images of cosmic transformation, the poet turns to the traditional icon colour combinations and reinterprets the Old and New Testaments images. It puts the cases of prophet Sergei Yesenin in line with the acts of the biblical prophets. All poems in their colour scheme are consistent with iconographic tradition. In these poems three basic colours are used which repeat the colours of thematically close icons. So, Th e Coming is coloristically associated with the icon of the Nativity, The Transfiguration corresponds to the eponymous icon of Christ. The colours show the relationship and the parallelism of the processes occurring in earthly and heavenly worlds. It emphasizes the unity of the poetic world, the engagement of the Earth and the Heaven in the conversion process. The consideration of Yesenin’s revolutionary epic in line with biblical and iconographic symbolism allows analyzing in a more detailed and deep way originality of poetic recreation of the World and enables to reveal philosophical and esoteric content of the works.

  17. Brilliant Star in a Colourful Neighbourhood

    Science.gov (United States)

    2010-07-01

    A spectacular new image from ESO's Wide Field Imager at the La Silla Observatory in Chile shows the brilliant and unusual star WR 22 and its colourful surroundings. WR 22 is a very hot and bright star that is shedding its atmosphere into space at a rate many millions of times faster than the Sun. It lies in the outer part of the dramatic Carina Nebula from which it formed. Very massive stars live fast and die young. Some of these stellar beacons have such intense radiation passing through their thick atmospheres late in their lives that they shed material into space many millions of times more quickly than relatively sedate stars such as the Sun. These rare, very hot and massive objects are known as Wolf-Rayet stars [1], after the two French astronomers who first identified them in the mid-nineteenth century, and one of the most massive ones yet measured is known as WR 22. It appears at the centre of this picture, which was created from images taken through red, green and blue filters with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. WR 22 is a member of a double star system and has been measured to have a mass at least 70 times that of the Sun. WR 22 lies in the southern constellation of Carina, the keel of Jason's ship Argo in Greek mythology. Although the star lies over 5000 light-years from the Earth it is so bright that it can just be faintly seen with the unaided eye under good conditions. WR 22 is one of many exceptionally brilliant stars associated with the beautiful Carina Nebula (also known as NGC 3372) and the outer part of this huge region of star formation in the southern Milky Way forms the colourful backdrop to this image. The subtle colours of the rich background tapestry are a result of the interactions between the intense ultraviolet radiation coming from hot massive stars, including WR 22, and the vast gas clouds, mostly hydrogen, from which they formed. The central part of this enormous complex

  18. Facial Identification in Observers with Colour-Grapheme Synaesthesia

    DEFF Research Database (Denmark)

    Sørensen, Thomas Alrik

    2013-01-01

    suggested as an explanation of a neural substrate of synaesthesia. The present study does not have a strong point on this view. However, as the fusiform gyrus also have been proposed to play a crucial role in the processing of facial features for identification [e.g. Kanwisher et al, 1997, The Journal...... of Neuroscience, 17(11), 4302–4311], increased colour-word form representations in observers with colour-grapheme synaesthesia may affect facial identification in people with synaesthesia. This study investigates the ability to process facial features for identification in observers with colour...

  19. Skin blood perfusion and oxygenation colour affect perceived human health.

    Directory of Open Access Journals (Sweden)

    Ian D Stephen

    Full Text Available Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice.

  20. Grapheme-colour synaesthesia improves detection of embedded shapes, but without pre-attentive 'pop-out' of synaesthetic colour.

    Science.gov (United States)

    Ward, Jamie; Jonas, Clare; Dienes, Zoltan; Seth, Anil

    2010-04-07

    For people with synaesthesia letters and numbers may evoke experiences of colour. It has been previously demonstrated that these synaesthetes may be better at detecting a triangle made of 2s among a background of 5s if they perceive 5 and 2 as having different synaesthetic colours. However, other studies using this task (or tasks based on the same principle) have failed to replicate the effect or have suggested alternative explanations of the effect. In this study, we repeat the original study on a larger group of synaesthetes (n = 36) and include, for the first time, an assessment of their self-reported colour experiences. We show that synaesthetes do have a general advantage over controls on this task. However, many synaesthetes report no colour experiences at all during the task. Synaesthetes who do report colour typically experience around one third of the graphemes in the display as coloured. This is more consistent with theories of synaesthesia in which spatial attention needs to be deployed to graphemes for conscious colour experiences to emerge than the interpretation based on 'pop-out'.

  1. Colouring cryo-cooled crystals: online microspectrophotometry

    Energy Technology Data Exchange (ETDEWEB)

    McGeehan, John [EMBL, 6 rue Jules Horowitz, 38042 Grenoble (France); Biophysics Laboratories, School of Biological Sciences, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth PO1 2DY (United Kingdom); Ravelli, Raimond B. G., E-mail: ravelli@lumc.nl [EMBL, 6 rue Jules Horowitz, 38042 Grenoble (France); Section Electron Microscopy, Department of Molecular Cell Biology, Leiden University Medical Center (LUMC), PO Box 9600, 2300RC Leiden (Netherlands); Murray, James W. [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom); Imperial College, Exhibition Road, London SW7 2AZ (United Kingdom); Owen, Robin Leslie [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom); Cipriani, Florent [EMBL, 6 rue Jules Horowitz, 38042 Grenoble (France); McSweeney, Sean [ESRF, 6 rue Jules Horowitz, 38043 Grenoble (France); Weik, Martin [Laboratoire de Biophysique Moléculaire, Institut de Biologie Structurale, Jean Pierre EBEL, 41 rue Jules Horowitz, 38027 Grenoble Cedex 1 (France); Garman, Elspeth F., E-mail: ravelli@lumc.nl [Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom)

    2009-03-01

    A portable and readily aligned online microspectrophotometer that can be easily installed on macromolecular crystallography beamlines is described. It allows measurement of the spectral characteristics of macromolecular crystals prior, during, and after the X-ray diffraction experiment. X-rays can produce a high concentration of radicals within cryo-cooled macromolecular crystals. Some radicals have large extinction coefficients in the visible (VIS) range of the electromagnetic spectrum, and can be observed optically and spectrally. An online microspectrophotometer with high temporal resolution has been constructed that is capable of measuring UV/VIS absorption spectra (200–1100 nm) during X-ray data collection. The typical X-ray-induced blue colour that is characteristic of a wide range of cryo-conditions has been identified as trapped solvated electrons. Disulphide-containing proteins are shown to form disulphide radicals at millimolar concentrations, with absorption maxima around 400 nm. The solvated electrons and the disulphide radicals seem to have a lifetime in the range of seconds up to minutes at 100 K. The temperature dependence of the kinetics of X-ray-induced radical formation is different for the solvated electrons compared with the disulphide radicals. The online microspectrophotometer provides a technique complementary to X-ray diffraction for analysing and characterizing intermediates and redox states of proteins and enzymes.

  2. When Colour Matters: Policing and Hate Crime

    Directory of Open Access Journals (Sweden)

    Berit Wigerfelt

    2014-04-01

    Full Text Available Contrary to the image of Sweden as a tolerant, colour-blind and non-racial country, which is based on the narrative of a country for instance associated with solidarity with the so-called Third World; in this article we argue that racial attributes, e.g. visible differences, account for people’s different life possibilities and circumstances in Swedish society. This article explores and discusses whether, and if so why, people who belong to the group that is categorised as “non-white”, with an emphasis on Afroswedes, and depicted as racially different, experience being targets of diverse variations of bias-based policing, harassment and hate crime. Theories relating to colonial stereotypes, racism, doing difference, the geography of hate, race/ethnicity profiling and intersectionality are used to analyse our material. Based on individual and focus group interviews with “non-whites”, this article discusses how visible differences are highlighted in different kinds of social contexts. The interview results show that people with dark skin are often targets of different kinds of private and public policing based on race- and ethnicity profiling that often occurs on or near borders/boundaries. When those who are targets of racial harassment and exclusion resist such treatment, e.g. by crossing borders/boundaries, they are at risk of becoming victims of hate crime.

  3. When Colour Matters: Policing and Hate Crime

    Directory of Open Access Journals (Sweden)

    Berit Wigerfelt

    2014-04-01

    Full Text Available Contrary to the image of Sweden as a tolerant, colour-blind and non-racial country, which is based on the narrative of a country for instance associated with solidarity with the so-called Third World; in this article we argue that racial attributes, e.g. visible differences, account for people’s different life possibilities and circumstances in Swedish society. This article explores and discusses whether, and if so why, people who belong to the group that is categorised as “non-white”, with an emphasis on Afroswedes, and depicted as racially different, experience being targets of diverse variations of bias-based policing, harassment and hate crime. Theories relating to colonial stereotypes, racism, doing difference, the geography of hate, race/ethnicity profiling and intersectionality are used to analyse our material. Based on individual and focus group interviews with “non-whites”, this article discusses how visible differences are highlighted in different kinds of social contexts. The interview results show that people with dark skin are often targets of different kinds of private and public policing based on race- and ethnicity profiling that often occurs on or near borders/boundaries. When those who are targets of racial harassment and exclusion resist such treatment, e.g. by crossing borders/boundaries, they are at risk of becoming victims of hate crime.

  4. QCD breaks Lorentz invariance and colour

    Science.gov (United States)

    Balachandran, A. P.

    2016-03-01

    In the previous work [A. P. Balachandran and S. Vaidya, Eur. Phys. J. Plus 128, 118 (2013)], we have argued that the algebra of non-Abelian superselection rules is spontaneously broken to its maximal Abelian subalgebra, that is, the algebra generated by its completing commuting set (the two Casimirs, isospin and a basis of its Cartan subalgebra). In this paper, alternative arguments confirming these results are presented. In addition, Lorentz invariance is shown to be broken in quantum chromodynamics (QCD), just as it is in quantum electrodynamics (QED). The experimental consequences of these results include fuzzy mass and spin shells of coloured particles like quarks, and decay life times which depend on the frame of observation [D. Buchholz, Phys. Lett. B 174, 331 (1986); D. Buchholz and K. Fredenhagen, Commun. Math. Phys. 84, 1 (1982; J. Fröhlich, G. Morchio and F. Strocchi, Phys. Lett. B 89, 61 (1979); A. P. Balachandran, S. Kürkçüoğlu, A. R. de Queiroz and S. Vaidya, Eur. Phys. J. C 75, 89 (2015); A. P. Balachandran, S. Kürkçüoğlu and A. R. de Queiroz, Mod. Phys. Lett. A 28, 1350028 (2013)]. In a paper under preparation, these results are extended to the ADM Poincaré group and the local Lorentz group of frames. The renormalisation of the ADM energy by infrared gravitons is also studied and estimated.

  5. Methods for Determining Organic Matter and Colour in Water

    Directory of Open Access Journals (Sweden)

    Ramunė Albrektienė

    2011-02-01

    Full Text Available The article examines different methods for determining organic matter and colour in water. Most of organic compounds in water have a humic substance. These substances frequently form complexes with iron. Humic matter gives water a yellow-brownish colour. Water filtration through conventional sand filters does not remove colour and organic compounds, and therefore complicated water treatment methods shall be applied. The methods utilized for organic matter determination in water included research on total organic carbon, permanganate index and the bichromate number of UV absorption of 254 nm wave length. The obtained results showed the greatest dependence between water colour and permanganate index. However, UV adsorption could be used for organic matter determination during the operation of a water treatment plant and the start-up of plants as easy and fast methods.Article in Lithuanian

  6. Pseudo natural colour aerial imagery for urban and suburban mapping

    DEFF Research Database (Denmark)

    Knudsen, Thomas

    2005-01-01

    Due to their near-infrared data channel, digital airborne four-channel imagers provide a potentially good discrimination between vegetation and human-made materials, which is very useful in automated mapping. Due to their red, green and blue data channels, they also provide natural colour images......, which are very useful in traditional (manual) mapping. In this paper, an algorithm is described which provides an approximation to the spectral capabilities of the four-channel imagers by using a colour-infrared aerial photo as input. The algorithm is tailored to urban/suburban surroundings, where...... the quality of the generated (pseudo) natural colour images are fully acceptable for manual mapping. This brings the combined availability of near-infrared and (pseudo) natural colours within reach for mapping projects based on traditional photogrammetry, which is valuable since traditional analytical cameras...

  7. FIR colours and SEDs of nearby galaxies observed with Herschel

    CERN Document Server

    Boselli, A; Buat, V; Cortese, L; Auld, R; Baes, M; Bendo, G J; Bianchi, S; Bock, J; Bomans, D J; Bradford, M; Castro-Rodriguez, N; Chanial, P; Charlot, S; Clemens, M; Clements, D; Corbelli, E; Cooray, A; Cormier, D; Dariush, A; Davies, J; De Looze, I; Alighieri, S di Serego; Dwek, E; Eales, S; Elbaz, D; Fadda, D; Fritz, J; Galametz, M; Galliano, F; Garcia-Appadoo, D A; Gavazzi, G; Gear, W; Giovanardi, C; Glenn, J; Gomez, H; Griffin, M; Grossi, M; Hony, S; Hughes, T M; Hunt, L; Isaak, K; Jones, A; Levenson, L; Lu, N; Madden, S C; O'Halloran, B; Okumura, K; Oliver, S; Page, M; Panuzzo, P; Papageorgiou, A; Parkin, T; Perez-Fournon, I; Pierini, D; Pohlen, M; Rangwala, N; Rigby, E; Roussel, H; Rykala, A; Sabatini, S; Sacchi, N; Sauvage, M; Schulz, B; Schirm, M; Smith, M W L; Spinoglio, L; Stevens, J; Sundar, S; Symeonidis, M; Trichas, M; Vaccari, M; Verstappen, J; Vigroux, L; Vlahakis, C; Wilson, C; Wozniak, H; Wright, G; Xilouris, E M; Zeilinger, W; Zibetti, S

    2010-01-01

    We present infrared colours (in the 25-500 mic spectral range) and UV to radio continuum spectral energy distributions of a sample of 51 nearby galaxies observed with SPIRE on Herschel. The observed sample includes all morphological classes, from quiescent ellipticals to active starbursts. Active galaxies have warmer colour temperatures than normal spirals. In ellipticals hosting a radio galaxy, the far-infrared (FIR) emission is dominated bynthe synchrotron nuclear emission. The colour temperature of the cold dust is higher in quiescent E-S0a than in star-forming systems probably because of the different nature of their dust heating sources (evolved stellar populations, X-ray, fast electrons) and dust grain properties. In contrast to the colour temperature of the warm dust, the f350/f500 index sensitive to the cold dust decreases with star formation and increases with metallicity, suggesting an overabundance of cold dust or an emissivity parameter beta<2 in low metallicity, active systems.

  8. Effect of dietary vitamin E supplementation on lipid and colour ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-04-12

    Apr 12, 2010 ... and colour stability of fresh chicken thigh meat exposed in a supermarket shopwindow or stored in a ... Peroxide value (PV) and oxidation products specific extinctions ..... assessment of spoilage in three Beef muscles. Meat ...

  9. The colour of plant reproduction: A macroecological perspective

    Directory of Open Access Journals (Sweden)

    Kevin C. Burns

    2015-10-01

    Full Text Available Flowers and fruits are often vividly coloured. An obvious explanation for fruit and flower pigmentation is that it serves to attract animal mutualists. However, decades of research has produced surprising little support for this hypothesis. Exciting new research into geographic variation in flower colours suggests an alternative explanation - flower pigments protect gametes against the damaging effects of solar radiation. Here, I present several new analyses suggesting that a similar explanation might apply to Rubus spectabilis, a much studied but poorly understood bird-dispersed fruit species. These and other recent results provide a new perspective on the colour of plant reproduction. In addition to signalling to animals, fruit and flower colours might often play vital roles in protecting plants against the harmful effects of solar radiation.

  10. Anthocyanin and antioxidant activity of snacks with coloured potato.

    Science.gov (United States)

    Nemś, Agnieszka; Pęksa, Anna; Kucharska, Alicja Z; Sokół-Łętowska, Anna; Kita, Agnieszka; Drożdż, Wioletta; Hamouz, Karel

    2015-04-01

    Coloured-fleshed potatoes of four varieties were used as raw material for coloured flour and fried snack production. The effects of thermal processes traditionally used in dried potato processing and in snack pellet manufacturing on anthocyanin profiles, total polyphenols and antioxidant properties of obtained half- and ready products were studied. There was a significant influence of potato variety on the experimental flour and snack properties. Flours with the highest antioxidant activities were obtained from Salad Blue and Herbie 26 potatoes; however, the flour prepared from the Blue Congo exhibited a much higher total polyphenol and anthocyanin content. Snacks produced with coloured flour had 2-3 times higher antioxidant activities, 40% higher contents of polyphenols, attractive colour and better expansion compared to control samples. The lowest losses of anthocyanins during snack processing were in snacks with flour from the purple-fleshed Blue Congo and red-fleshed Herbie 26. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Ripening stage and drying method affecting colour and quality ...

    African Journals Online (AJOL)

    STORAGESEVER

    Key words: Ber, drying method, post harvest quality, blanching, fruit colour, harvesting stage. ... ground following abscission, throwing stones and sticks into the trees, hitting ... of insect larva inside each individual fruits. .... Climate change and.

  12. Demosaicing images from colour cameras for digital image correlation

    Science.gov (United States)

    Forsey, A.; Gungor, S.

    2016-11-01

    Digital image correlation is not the intended use for consumer colour cameras, but with care they can be successfully employed in such a role. The main obstacle is the sparsely sampled colour data caused by the use of a colour filter array (CFA) to separate the colour channels. It is shown that the method used to convert consumer camera raw files into a monochrome image suitable for digital image correlation (DIC) can have a significant effect on the DIC output. A number of widely available software packages and two in-house methods are evaluated in terms of their performance when used with DIC. Using an in-plane rotating disc to produce a highly constrained displacement field, it was found that the bicubic spline based in-house demosaicing method outperformed the other methods in terms of accuracy and aliasing suppression.

  13. Career identities of first-year female coloured students

    African Journals Online (AJOL)

    Erna Kinsey

    female coloured students' career identity, at a higher education institution in the Eastern Cape .... among first-year students, such as gender, race, ethnicity and socio-economic status. ...... White Paper on Integrated National Disability. Strategy.

  14. Development of the springbok skin - colour pattern, hair slope and ...

    African Journals Online (AJOL)

    1988-05-19

    May 19, 1988 ... Development of the springbok skin - colour pattern, hair slope and horn rudiments in Antidorcas ... No work has evidently been published on the development of .... some specimens a banking-up of melanocytes against the.

  15. optimization of coagulation-flocculation process for colour removal ...

    African Journals Online (AJOL)

    user

    ... as an alternative for conventional coagulants that are widely used in dye wastewater treatment plants. ... biological treatment techniques used are aerobic degradation ... for colour removal from industrial wastewater due to its efficiency and ...

  16. Evaluation of colour space transformation suitability to optical temperature measurements

    Science.gov (United States)

    Ziemba, A.; Fornalik-Wajs, E.

    2016-09-01

    All optical measurement methods base on the image analysis and relation between the measured parameter and some image features. In Digital Particle Image Thermometry (DPIT), such relation represents a function between the temperature and particles’ colour (i.a. Thermochromic Liquid Crystals). For the quantitative data acquisition the “colour” information is necessary, therefore the colour spaces based on hue H are used. Due to the big number of numerical operations needed in the analysis, the choice of colour space transformation is significant due to the accuracy and computational time. In this paper commonly applied RGB to HSI colour spaces’ transformations were compared and evaluation of their suitability to temperature measurement was performed. Time of obtaining the final results was considered as the main criterion. Appropriate calculations were conducted and presented.

  17. Near-infrared extinction with discretised stellar colours

    CERN Document Server

    Juvela, M

    2015-01-01

    Several methods exist to convert near-infrared (NIR) stellar observations into extinction maps. We present a new method based on NIR multiband observations. The method uses a discretised version of the distribution of intrinsic stellar colours. A number of variations of the basic method are tested, and the results are compared to NICER calculations. When photometric errors are large, the results are close to those of NICER method but some advantages can be seen when the distribution of intrinsic colours cannot be described well with a single covariance matrix. A priori information about relative column density variations at sub-beam scales can result in a significant increase in accuracy. The results may be further improved by considering the magnitude dependence of the intrinsic colours. Thus, the new methods are useful mostly when photometric errors are small, the distribution of intrinsic colours is well known, or one has prior knowledge of the small-scale structures.

  18. The Language of Colour: Neurology and the Ineffable

    Directory of Open Access Journals (Sweden)

    Nicholas Unwin

    2012-11-01

    Full Text Available It is often claimed, following Joseph Levine, that there is an ‘explanatory gap’ between ordinary physical facts and the way we perceive things, so that it is impossible to explain, among other things, why colours actually look the way they do. C.L. Hardin, by contrast, argues that there are sufficient asymmetries between colours to traverse this gap. This paper argues that the terms we use to characterize colours, such as ‘warm’ and ‘cool’, are not well understood, and that we need to understand the neurological basis for such associations if we are even to understand what is fully meant by saying, for example, that red is a warm colour. This paper also speculates on how Hardin’s strategy can be generalized.

  19. Achieving Harmonious Colour Relationship in Art/Design: Towards ...

    African Journals Online (AJOL)

    Nneka Umera-Okeke

    2011-12-06

    Dec 6, 2011 ... wide-range of colour concepts that are not kept distinct, contradictions ... A model (functional, graphical, mathematical, structural or verbal) is a ... particularly so when the model could easily be internalized and become intuitive.

  20. Multiple Illuminant Colour Estimation via Statistical Inference on Factor Graphs.

    Science.gov (United States)

    Mutimbu, Lawrence; Robles-Kelly, Antonio

    2016-08-31

    This paper presents a method to recover a spatially varying illuminant colour estimate from scenes lit by multiple light sources. Starting with the image formation process, we formulate the illuminant recovery problem in a statistically datadriven setting. To do this, we use a factor graph defined across the scale space of the input image. In the graph, we utilise a set of illuminant prototypes computed using a data driven approach. As a result, our method delivers a pixelwise illuminant colour estimate being devoid of libraries or user input. The use of a factor graph also allows for the illuminant estimates to be recovered making use of a maximum a posteriori (MAP) inference process. Moreover, we compute the probability marginals by performing a Delaunay triangulation on our factor graph. We illustrate the utility of our method for pixelwise illuminant colour recovery on widely available datasets and compare against a number of alternatives. We also show sample colour correction results on real-world images.

  1. COLOUR CULTURE AND IDENTITY: INFLUENCE OF COLOURS ON KERALA MURAL ART

    OpenAIRE

    Ravi, Sandhya

    2015-01-01

    The word ‘mural’ is derived from the Latin word ‘murus’, meaning ‘wall’. Murals refer to paintings embellished on visual components like the wall, ceiling, or other huge lasting surfaces. The murals of Kerala unfathomably stand out for their prominence in beauty, clarity and symmetry with unmatchable linear accuracy. The tradition of mural painting in Kerala is unique in the world, and it is extremely rich with symbolism. Made only with natural mineral pigments, the colours represent the qual...

  2. Defects of colour vision: A review of congenital and acquired colour vision deficiencies

    Directory of Open Access Journals (Sweden)

    Nabeela Hasrod

    2016-03-01

    Full Text Available Colour vision deficiencies (CVDs can be categorised as being congenital or acquired. Some CVDs are already present at birth, as inherited conditions that are the result of changes at the photo-pigment level and are non-pathological, incurable and do not change over time. Examples are red-green defects which are inherited as an X-linked recessive trait. Acquired CVD develops secondary to ocular and systemic conditions or as a side effect of certain medications or sometimes toxic effects of chemicals, and trauma and ageing can also be important in some CVDs.

  3. Effect of the diameter and colour of colorimeter aperture reducing templates on colour coordinate measurements

    Directory of Open Access Journals (Sweden)

    Robador, M. D.

    2008-09-01

    Full Text Available The colour coordinate values measured with the colorimeters presently on the market are the mean of the readings obtained for the surface area covered by the light projection tube. When the colour of the surface measured is not uniform, such as in the case of stone, the larger the tube aperture the more representative is the colour measurement, for a larger area is involved. While this is often an advantage, when the area studied is smaller than the aperture of the colorimeter used, the values obtained include unwanted information. One possible way to deal with this drawback is by using templates to reduce the measurement area. Templates adapted to a Minolta CR-210 colorimeter were tested in the present study. The conclusion drawn was that in addition to being convenient to use, they ensured that the readings matched the original colour of the surface, i.e., the value that would have been obtained without the templates.En los colorímetros que existen en el mercado, la luz se recoge mediante un tubo de cierto diámetro y los valores de las coordenadas cromáticas que da el medidor son una media de las obtenidas en dicha superficie. Cuando la superficie a medir no tiene un color uniforme, como ocurre en el caso de los materiales pétreos, la medida de color es más representativa cuanto mayor es la apertura del tubo de medida ya que la superficie medida es mayor. Este hecho, que en ocasiones supone una ventaja, presenta el inconveniente de que cuando la superficie objeto de estudio es inferior a la apertura del tubo de proyección del colorímetro utilizado, los valores obtenidos integran zonas no deseadas. Una posible solución a este inconveniente es la utilización de plantillas que reduzcan el área de medida. En este trabajo se ensayan plantillas adaptadoras del tubo de medida de un colorímetro Minolta CR-210, y se llega a la conclusión de que su uso, además de fácil, permite obtener el color original de la superficie medida, es decir

  4. Sensory adaptation. Tunable colour vision in a mantis shrimp.

    Science.gov (United States)

    Cronin, T W; Caldwell, R L; Marshall, J

    2001-05-31

    Systems of colour vision are normally identical in all members of a species, but a single design may not be adequate for species living in a diverse range of light environments. Here we show that in the mantis shrimp Haptosquilla trispinosa, which occupies a range of depths in the ocean, long-wavelength colour receptors are individually tuned to the local light environment. The spectral sensitivity of specific classes of photoreceptor is adjusted by filters that vary between individuals.

  5. Predicting Visible Image Degradation by Colour Image Difference Formulae

    Institute of Scientific and Technical Information of China (English)

    Eriko Bando; Jon Y. Hardeberg; David Connah; Ivar Farup

    2004-01-01

    It carried out a CRT monitor based psychophysical experiment to investigate the quality of three colour image difference metrics, the CIEAE ab equation, the iCAM and the S-CIELAB metrics. Six original images were reproduced through six gamut mapping algorithms for the observer experiment. The result indicates that the colour image difference calculated by each metric does not directly relate to perceived image difference.

  6. Molecular characterisation of colour formation in the prawn Fenneropenaeus merguiensis.

    Directory of Open Access Journals (Sweden)

    Nicole G Ertl

    Full Text Available INTRODUCTION: Body colouration in animals can have a range of functions, with predator protection an important aspect of colour in crustaceans. Colour determination is associated with the carotenoid astaxanthin, which is taken up through the diet and stabilised in the tissues by the protein crustacyanin. As a variety of genes are found to play a role in colour formation in other systems, a holistic approach was employed in this study to determine the factors involved in Fenneropenaeus merguiensis colouration. RESULTS: Full length F. merguiensis crustacyanin subunit A and C sequences were isolated. Crustacyanin subunit A and C were found in the F. merguiensis transcriptomes of the muscle/cuticle tissue, hepatopancreas, eye stalk and nervous system, using 454 next generation sequencing technology. Custom microarray analysis of albino, light and dark F. merguiensis cuticle tissue showed genes encoding actin, sarcoplasmic calcium-binding protein and arginine kinase to be 4-fold or greater differentially expressed (p<0.05 and down-regulated in albinos when compared to light and dark samples. QPCR expression analysis of crustacyanin and total astaxanthin pigment extraction revealed significantly (p<0.05 lower crustacyanin subunit A and C gene transcript copy numbers and total astaxanthin levels in albinos than in the light and dark samples. Additionally, crustacyanin subunit A and C expression levels correlated positively with each other. CONCLUSIONS: This study identified gene products putatively involved in crustacean colouration, such as crustacyanin, sarcoplasmic calcium-binding protein and forms of actin, and investigated differences in gene expression and astaxanthin levels between albino, light and dark coloured prawns. These genes open a path to enhance our understanding of the biology and regulation of colour formation.

  7. Investigation of a 2-Colour Undulator FEL Using Puffin

    CERN Document Server

    Campbell, L T; Reiche, S

    2013-01-01

    Initial studies of a 2-colour FEL amplifier using one monoenergetic electron beam are presented. The interaction is modelled using the unaveraged, broadband FEL code Puffin. A series of undulator modules are tuned to generate two resonant frequencies along the FEL interaction and a self-consistent 2-colour FEL interaction at widely spaced non-harmonic wavelengths at 1nm and 2.4nm is demonstrated.

  8. Does avian conspicuous colouration increase or reduce predation risk?

    Science.gov (United States)

    Ruiz-Rodríguez, M; Avilés, J M; Cuervo, J J; Parejo, D; Ruano, F; Zamora-Muñoz, C; Sergio, F; López-Jiménez, L; Tanferna, A; Martín-Vivaldi, M

    2013-09-01

    Animals often announce their unprofitability to predators through conspicuous coloured signals. Here we tested whether the apparently conspicuous colour designs of the four European Coraciiformes and Upupiformes species may have evolved as aposematic signals, or whether instead they imply a cost in terms of predation risk. Because previous studies suggested that these species are unpalatable, we hypothesized that predators could avoid targeting them based on their colours. An experiment was performed where two artificial models of each bird species were exposed simultaneously to raptor predators, one painted so as to resemble the real colour design of these birds, and the other one painted using cryptic colours. Additionally, we used field data on the black kite's diet to compare the selection of these four species to that of other avian prey. Conspicuous models were attacked in equal or higher proportions than their cryptic counterparts, and the attack rate on the four species increased with their respective degree of contrast against natural backgrounds. The analysis of the predator's diet revealed that the two least attacked species were negatively selected in nature despite their abundance. Both conspicuous and cryptic models of one of the studied species (the hoopoe) received fewer attacks than cryptic models of the other three species, suggesting that predators may avoid this species for characteristics other than colour. Globally, our results suggest that the colour of coraciiforms and upupiforms does not function as an aposematic signal that advises predators of their unprofitability, but also that conspicuous colours may increase predation risk in some species, supporting thus the handicap hypothesis.

  9. Warmth perception in association with colour and material

    OpenAIRE

    Ulusoy, Begüm

    2016-01-01

    Cataloged from PDF version of article. Thesis (Ph.D.): Bilkent University, Department of Interior Architecture and Environmental Design, İhsan Doğramacı Bilkent University, 2016. Includes bibliographical references (leaves 168-178). Warmth perception is physical, emotional, semantic, and sensorial bond between people and their environments. Warmth is a prominent characteristic of interior architecture and is related to colours and materials. Although the effects of single colours and...

  10. The SAURON project - XX. The Spitzer [3.6] - [4.5] colour in early-type galaxies: colours, colour gradients and inverted scaling relations

    Science.gov (United States)

    Peletier, Reynier F.; Kutdemir, Elif; van der Wolk, Guido; Falcón-Barroso, Jesús; Bacon, Roland; Bureau, Martin; Cappellari, Michele; Davies, Roger L.; de Zeeuw, P. Tim; Emsellem, Eric; Krajnović, Davor; Kuntschner, Harald; McDermid, Richard M.; Sarzi, Marc; Scott, Nicholas; Shapiro, Kristen L.; van den Bosch, Remco C. E.; van de Ven, Glenn

    2012-01-01

    We investigate the [3.6]-[4.5] Spitzer-IRAC colour behaviour of the early-type galaxies of the SAURON survey, a representative sample of 48 nearby ellipticals and lenticulars. We investigate how this colour, which is unaffected by dust extinction, can be used to constrain the stellar populations in these galaxies. We find a tight relation between the [3.6]-[4.5] colour and effective velocity dispersion, a good mass indicator in early-type galaxies: ([3.6]-[4.5])e = (-0.109 ? 0.007)?+ (0.154 ? 0.016). Contrary to other colours in the optical and near-infrared, we find that the colours become bluer for larger galaxies. The relations are tighter when using the colour inside re (scatter 0.013 mag), rather than the much smaller re/8 aperture (scatter 0.023 mag), due to the presence of young populations in the central regions. We also obtain strong correlations between the [3.6]-[4.5] colour and three strong absorption lines (H?, Mgb and Fe 5015). Comparing our data with the models of Marigo et al., which show that more metal rich galaxies are bluer, we can explain our results in a way consistent with results from the optical, by stating that larger galaxies are more metal rich. The blueing is caused by a strong CO absorption band, whose line strength increases strongly with decreasing temperature and which covers a considerable fraction of the 4.5-?m filter. In galaxies that contain a compact radio source, the [3.6]-[4.5] colour is generally slightly redder (by 0.015 ? 0.007 mag using the re/8 aperture) than in the other galaxies, indicating small amounts of either hot dust, non-thermal emission, or young stars near the centre. We find that the large majority of the galaxies show redder colours with increasing radius. Removing the regions with evidence for young stellar populations (from the H? absorption line) and interpreting the colour gradients as metallicity gradients, we find that our galaxies are more metal poor going outwards. The radial [3.6]-[4.5] gradients

  11. The unsuitability of HTML-based colour charts for estimating animal colours--a comment on Berggren and Merilä (2004).

    Science.gov (United States)

    Stevens, Martin; Cuthill, Innes C

    2005-08-30

    A variety of techniques are used to study the colours of animal signals, including the use of visual matching to colour charts. This paper aims to highlight why they are generally an unsatisfactory tool for the measurement and classification of animal colours and why colour codes based on HTML (really RGB) standards, as advocated in a recent paper, are particularly inappropriate. There are many theoretical arguments against the use of colour charts, not least that human colour vision differs markedly from that of most other animals. However, the focus of this paper is the concern that, even when applied to humans, there is no simple 1:1 mapping from an RGB colour space to the perceived colours in a chart (the results are both printer- and illumination-dependent). We support our criticisms with data from colour matching experiments with humans, involving self-made, printed colour charts. Colour matching experiments with printed charts involving 11 subjects showed that the choices made by individuals were significantly different between charts that had exactly the same RGB values, but were produced from different printers. Furthermore, individual matches tended to vary under different lighting conditions. Spectrophotometry of the colour charts showed that the reflectance spectra of the charts varied greatly between printers and that equal steps in RGB space were often far from equal in terms of reflectance on the printed charts. In addition to outlining theoretical criticisms of the use of colour charts, our empirical results show that: individuals vary in their perception of colours, that different printers produce strikingly different results when reproducing what should be the same chart, and that the characteristics of the light irradiating the surface do affect colour perception. Therefore, we urge great caution in the use of colour charts to study animal colour signals. They should be used only as a last resort and in full knowledge of their limitations, with

  12. The unsuitability of html-based colour charts for estimating animal colours – a comment on Berggren and Merilä (2004

    Directory of Open Access Journals (Sweden)

    Cuthill Innes C

    2005-08-01

    Full Text Available Abstract Background A variety of techniques are used to study the colours of animal signals, including the use of visual matching to colour charts. This paper aims to highlight why they are generally an unsatisfactory tool for the measurement and classification of animal colours and why colour codes based on HTML (really RGB standards, as advocated in a recent paper, are particularly inappropriate. There are many theoretical arguments against the use of colour charts, not least that human colour vision differs markedly from that of most other animals. However, the focus of this paper is the concern that, even when applied to humans, there is no simple 1:1 mapping from an RGB colour space to the perceived colours in a chart (the results are both printer- and illumination-dependent. We support our criticisms with data from colour matching experiments with humans, involving self-made, printed colour charts. Results Colour matching experiments with printed charts involving 11 subjects showed that the choices made by individuals were significantly different between charts that had exactly the same RGB values, but were produced from different printers. Furthermore, individual matches tended to vary under different lighting conditions. Spectrophotometry of the colour charts showed that the reflectance spectra of the charts varied greatly between printers and that equal steps in RGB space were often far from equal in terms of reflectance on the printed charts. Conclusion In addition to outlining theoretical criticisms of the use of colour charts, our empirical results show that: individuals vary in their perception of colours, that different printers produce strikingly different results when reproducing what should be the same chart, and that the characteristics of the light irradiating the surface do affect colour perception. Therefore, we urge great caution in the use of colour charts to study animal colour signals. They should be used only as a last

  13. The sensitivity of RpA to colour recombination effects

    Science.gov (United States)

    Zapp, Korinna Christina; Milhano, Guilherme; Wiedemann, Urs Achim

    2016-12-01

    In hadronization models with colour recombination, partons are allowed to regroup into colour singlet structures that are different from those determined by the perturbative parton shower. This aims at modeling the possibility that soft interactions of partons with the underlying event can change colour connections. If such an effect is at play in proton-proton collisions, it may be expected to be enhanced in proton-nucleus collisions due to the higher colour charge density in the underlying event. Here, we provide a qualitative argument that colour recombination effects could lead to a multiplicity dependent hardening of single inclusive hadron spectra that dies out very weakly (∝ 1 /p⊥) with increasing transverse momentum. We present results of a (conservative) model implementation in the cluster hadronization model of the SHERPA event generator. In this model, we find that colour recombination effects harden indeed the single inclusive hadron spectra without affecting the jet spectra, but that this effect does not depend significantly on underlying event activity. We explain this model feature and we argue why, in general, data on proton-nucleus collisions can help to constrain hadronization models used in proton-proton event generators.

  14. Plant scents modify innate colour preference in foraging swallowtail butterflies.

    Science.gov (United States)

    Yoshida, Mina; Itoh, Yuki; Ômura, Hisashi; Arikawa, Kentaro; Kinoshita, Michiyo

    2015-07-01

    Flower-visiting insects exhibit innate preferences for particular colours. A previous study demonstrated that naive Papilio xuthus females prefer yellow and red, whereas males are more attracted to blue. Here, we demonstrate that the innate colour preference can be modified by olfactory stimuli in a sexually dimorphic manner. Naive P. xuthus were presented with four coloured discs: blue, green, yellow and red. The innate colour preference (i.e. the colour first landed on) of the majority of individuals was blue. When scent from essential oils of either orange flower or lily was introduced to the room, females' tendency to select the red disc increased. Scents of lavender and flowering potted Hibiscus rosa-sinensis, however, were less effective. Interestingly, the odour of the non-flowering larval host plant, Citrus unshiu, shifted the preference to green in females. In males, however, all plant scents were less effective than in females, such that blue was always the most favoured colour. These observations indicate that interactions between visual and olfactory cues play a more prominent role in females. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  15. Dichromatic colour vision in an Australian marsupial, the tammar wallaby.

    Science.gov (United States)

    Hemmi, J M

    1999-12-01

    Despite earlier assertions that most mammals are colour blind, colour vision has in recent years been demonstrated in a variety of eutherian mammals from a wide range of different orders. This paper presents the first behavioural evidence from colour discrimination experiments, that an Australian marsupial, the tammar wallaby (Macropus eugenii), has dichromatic colour vision. In addition, the experiments show that the wallabies readily learn the relationship between the presented colours rather than the absolute hues. This provides a sensitive method to measure the location of the neutral-point, which is the wavelength of monochromatic light that is indistinguishable from white. This point is a diagnostic feature for dichromats. The spectral sensitivity of the wallabies' middle-wavelength-sensitive photoreceptor is known (peak: 539 nm) and the behavioural results imply that the sensitivity of the short-wavelength-sensitive receptor must be near 420 nm. These spectral sensitivities are similar to those found in eutherian mammals, supporting the view that the earliest mammals had dichromatic colour vision.

  16. The colour analysis method applied to homogeneous rocks

    Directory of Open Access Journals (Sweden)

    Halász Amadé

    2015-12-01

    Full Text Available Computer-aided colour analysis can facilitate cyclostratigraphic studies. Here we report on a case study involving the development of a digital colour analysis method for examination of the Boda Claystone Formation which is the most suitable in Hungary for the disposal of high-level radioactive waste. Rock type colours are reddish brown or brownish red, or any shade between brown and red. The method presented here could be used to differentiate similar colours and to identify gradual transitions between these; the latter are of great importance in a cyclostratigraphic analysis of the succession. Geophysical well-logging has demonstrated the existence of characteristic cyclic units, as detected by colour and natural gamma. Based on our research, colour, natural gamma and lithology correlate well. For core Ib-4, these features reveal the presence of orderly cycles with thicknesses of roughly 0.64 to 13 metres. Once the core has been scanned, this is a time- and cost-effective method.

  17. Plant scents modify innate colour preference in foraging swallowtail butterflies

    Science.gov (United States)

    Yoshida, Mina; Itoh, Yuki; Ômura, Hisashi; Arikawa, Kentaro; Kinoshita, Michiyo

    2015-01-01

    Flower-visiting insects exhibit innate preferences for particular colours. A previous study demonstrated that naive Papilio xuthus females prefer yellow and red, whereas males are more attracted to blue. Here, we demonstrate that the innate colour preference can be modified by olfactory stimuli in a sexually dimorphic manner. Naive P. xuthus were presented with four coloured discs: blue, green, yellow and red. The innate colour preference (i.e. the colour first landed on) of the majority of individuals was blue. When scent from essential oils of either orange flower or lily was introduced to the room, females’ tendency to select the red disc increased. Scents of lavender and flowering potted Hibiscus rosa-sinensis, however, were less effective. Interestingly, the odour of the non-flowering larval host plant, Citrus unshiu, shifted the preference to green in females. In males, however, all plant scents were less effective than in females, such that blue was always the most favoured colour. These observations indicate that interactions between visual and olfactory cues play a more prominent role in females. PMID:26179802

  18. Colour asymmetry between galaxies with clockwise and counterclockwise handedness

    Science.gov (United States)

    Shamir, Lior

    2017-02-01

    Recent studies have shown that SDSS galaxies with clockwise patterns are photometrically different from galaxies with anti-clockwise patterns. The purpose of this study is to identify possible differences between the colour of galaxies with clockwise handedness and the colour of galaxies with anti-clockwise handedness. A dataset of 162,514 SDSS galaxies was separated into clockwise and counterclockwise galaxies, and the colours of spiral galaxies with clockwise handedness were compared to the colour of spiral galaxies with anti-clockwise handedness. The results show that the i-r colour in clockwise galaxies in SDSS is significantly higher compared to anti-clockwise SDSS galaxies. The colour difference is strongest between the right ascension of 30° and 60°, while the RA range of 180° to 210° shows a much smaller difference. Similarly, comparing other photometric measurements in clockwise and anti-clockwise galaxies exhibit statistically significant difference, showing the SDSS pipeline is sensitive to the handedness of the galaxy.

  19. Ruby coloured lead glasses by generation of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gil, C. [Fundacion Centro Nacional del Vidrio, Pocillo, 1, 40100 La Granja de San Ildefonso (Segovia) (Spain); Villegas, M.A. [Centro Nacional de Investigaciones Metalurgicas (CENIM), Spanish Council for Scientific Research (CSIC), Avda. Gregorio del Amo, 8, 28040 Madrid (Spain)]. E-mail: mavillegas@cenim.csic.es

    2004-11-15

    Both yellow and red superficial ruby lead crystal glasses have been obtained by Ag{sup +} ion-exchange. For red ruby colouring lead glass substrates were previously doped with reducing oxides (arsenic, antimony, cerium and tin). The best experimental conditions for silver ion-exchange were determined. The optical absorption behaviour of the samples was studied to point out the influence of the parameters involved in the ion-exchange process. Moreover, other parameters affecting the final colouring of the glasses (kind of dopant, dopant concentration, etc.) were also analysed. The dopant percentage added to the lead crystal glass is the most important factor for developing superficial red ruby colouring. Antimony oxide doped lead glass ion-exchanged with silver showed the most intense red ruby colouring, even for a doping concentration lower than those of arsenic oxide doped samples able to enhance similar colour. Spectral saturation appeared for the highest doping concentration and for the most severe ion-exchange conditions. Chromatic coordinates were calculated from the corresponding transmission visible spectra. The colour purity showed by the samples obtained satisfies the ornamental requirements that motivated this research.

  20. Colourface - coloured facades for solar heating systems and building insulation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, T.; Wagner, W.; Hausner, R. [AEE INTEC, Gleisdorf (Austria); Koehl, M.; Herkel, S. [Fraunhofer ISE, Freiburg (Germany); Orel, B. [National Inst. of Chemistry, Ljubljana (Slovenia); Hoefler, K. [TB fuer Bauphysik, Graz (Austria)

    2004-07-01

    Coloured absorbers are a major demand of architects for the design of facade integrated solar thermal collectors. But coloured absorbers have shown an inferior thermal performance compared to selective coatings of state-of-the-art collectors so far. Within the project Colourface selective colour coatings have been developed and ageing tests of the coatings have been performed. Four colours have been chosen as absorber coatings for test collectors. The colours were blue, green, auburn and grey. The efficiency of these test collectors was measured using the dynamic collector test method according to EN 12975-2. The blue and green coloured absorbers have shown thermal performances comparable to black solar varnish coated absorbers. The auburn coating showed less absorptivity but also less emissivity than blue and green resulting in a slightly lower efficiency curve. The efficiency of the grey coated absorber was the lowest of all tested collectors as it was expected. Seven wall constructions that are commonly used in Austria and Germany have been investigated to find out whether the direct integration of collectors into the wall is possible without harming the building materials or. Finally, two pilot systems - a newly constructed two-family house and a retrofit building - have been realised with facade collectors. Temperatures and relative humidities in the collector and inside the wall construction have been monitored and analysed. The results of the project are presented in this paper. (orig.)

  1. Ultra-realistic 3-D imaging based on colour holography

    Science.gov (United States)

    Bjelkhagen, H. I.

    2013-02-01

    A review of recent progress in colour holography is provided with new applications. Colour holography recording techniques in silver-halide emulsions are discussed. Both analogue, mainly Denisyuk colour holograms, and digitally-printed colour holograms are described and their recent improvements. An alternative to silver-halide materials are the panchromatic photopolymer materials such as the DuPont and Bayer photopolymers which are covered. The light sources used to illuminate the recorded holograms are very important to obtain ultra-realistic 3-D images. In particular the new light sources based on RGB LEDs are described. They show improved image quality over today's commonly used halogen lights. Recent work in colour holography by holographers and companies in different countries around the world are included. To record and display ultra-realistic 3-D images with perfect colour rendering are highly dependent on the correct recording technique using the optimal recording laser wavelengths, the availability of improved panchromatic recording materials and combined with new display light sources.

  2. Towards Video Quality Metrics Based on Colour Fractal Geometry

    Directory of Open Access Journals (Sweden)

    Richard Noël

    2010-01-01

    Full Text Available Vision is a complex process that integrates multiple aspects of an image: spatial frequencies, topology and colour. Unfortunately, so far, all these elements were independently took into consideration for the development of image and video quality metrics, therefore we propose an approach that blends together all of them. Our approach allows for the analysis of the complexity of colour images in the RGB colour space, based on the probabilistic algorithm for calculating the fractal dimension and lacunarity. Given that all the existing fractal approaches are defined only for gray-scale images, we extend them to the colour domain. We show how these two colour fractal features capture the multiple aspects that characterize the degradation of the video signal, based on the hypothesis that the quality degradation perceived by the user is directly proportional to the modification of the fractal complexity. We claim that the two colour fractal measures can objectively assess the quality of the video signal and they can be used as metrics for the user-perceived video quality degradation and we validated them through experimental results obtained for an MPEG-4 video streaming application; finally, the results are compared against the ones given by unanimously-accepted metrics and subjective tests.

  3. Transitions in a genotype selection model driven by coloured noises

    Institute of Scientific and Technical Information of China (English)

    Wang Can-Jun; Mei Dong-Cheng

    2008-01-01

    This paper investigates a genotype selection model subjected to both a multiplicative coloured noise and an additive coloured noise with different correlation time T1 and T2 by means of the numerical technique.By directly simulating the Langevin Equation,the following results are obtained.(1) The multiplicative coloured noise dominates,however,the effect of the additive coloured noise is not neglected in the practical gene selection process.The selection rate μ decides that the selection is propitious to gene A haploid or gene B haploid.(2) The additive coloured noise intensity α and the correlation time T2 play opposite roles.It is noted that α and T2 can not separate the single peak,while αcan make the peak disappear and T2 can make the peak be sharp.(3) The multiplicative coloured noise intensity D and the correlation time T1 can induce phase transition,at the same time they play opposite roles and the reentrance phenomenon appears.In this case,it is easy to select one type haploid from the group with increasing D and decreasing T1.

  4. What triggers colour change? Effects of background colour and temperature on the development of an alpine grasshopper

    National Research Council Canada - National Science Library

    Valverde, J Pablo; Schielzeth, Holger

    2015-01-01

    .... Orthoptera, the insect group that encompasses grasshoppers and bush crickets, includes a particularly large number of species that are colour polymorphic with a marked green-brown polymorphism being...

  5. Synaesthetic Colour in the Brain: Beyond Colour Areas. A Functional Magnetic Resonance Imaging Study of Synaesthetes and Matched Controls

    NARCIS (Netherlands)

    Leeuwen, T.M. van; Petersson, K.M.; Hagoort, P.

    2010-01-01

    Background: In synaesthesia, sensations in a particular modality cause additional experiences in a second, unstimulated modality (e. g., letters elicit colour). Understanding how synaesthesia is mediated in the brain can help to understand normal processes of perceptual awareness and multisensory

  6. Bona fide colour: DNA prediction of human eye and hair colour from ancient and contemporary skeletal remains.

    Science.gov (United States)

    Draus-Barini, Jolanta; Walsh, Susan; Pośpiech, Ewelina; Kupiec, Tomasz; Głąb, Henryk; Branicki, Wojciech; Kayser, Manfred

    2013-01-14

    DNA analysis of ancient skeletal remains is invaluable in evolutionary biology for exploring the history of species, including humans. Contemporary human bones and teeth, however, are relevant in forensic DNA analyses that deal with the identification of perpetrators, missing persons, disaster victims or family relationships. They may also provide useful information towards unravelling controversies that surround famous historical individuals. Retrieving information about a deceased person's externally visible characteristics can be informative in both types of DNA analyses. Recently, we demonstrated that human eye and hair colour can be reliably predicted from DNA using the HIrisPlex system. Here we test the feasibility of the novel HIrisPlex system at establishing eye and hair colour of deceased individuals from skeletal remains of various post-mortem time ranges and storage conditions. Twenty-one teeth between 1 and approximately 800 years of age and 5 contemporary bones were subjected to DNA extraction using standard organic protocol followed by analysis using the HIrisPlex system. Twenty-three out of 26 bone DNA extracts yielded the full 24 SNP HIrisPlex profile, therefore successfully allowing model-based eye and hair colour prediction. HIrisPlex analysis of a tooth from the Polish general Władysław Sikorski (1881 to 1943) revealed blue eye colour and blond hair colour, which was positively verified from reliable documentation. The partial profiles collected in the remaining three cases (two contemporary samples and a 14th century sample) were sufficient for eye colour prediction. Overall, we demonstrate that the HIrisPlex system is suitable, sufficiently sensitive and robust to successfully predict eye and hair colour from ancient and contemporary skeletal remains. Our findings, therefore, highlight the HIrisPlex system as a promising tool in future routine forensic casework involving skeletal remains, including ancient DNA studies, for the prediction of

  7. Cross-modal associations in synaesthesia: Vowel colours in the ear of the beholder

    OpenAIRE

    Moos, Anja; Smith, Rachel; Miller, Sam R; Simmons, David R

    2014-01-01

    Human speech conveys many forms of information, but for some exceptional individuals (synaesthetes), listening to speech sounds can automatically induce visual percepts such as colours. In this experiment, grapheme–colour synaesthetes and controls were asked to assign colours, or shades of grey, to different vowel sounds. We then investigated whether the acoustic content of these vowel sounds influenced participants' colour and grey-shade choices. We found that both colour and grey-shade asso...

  8. What colour is my arm? Changes in skin colour of an embodied virtual arm modulates pain threshold

    Directory of Open Access Journals (Sweden)

    Matteo eMartini

    2013-07-01

    Full Text Available It has been demonstrated that visual inputs can modulate pain. However, the influence of skin colour on pain perception is unknown. Red skin is associated to inflamed, hot and more sensitive skin while blue is associated to cold. We aimed to test whether the colour of the skin would alter the heat pain threshold. To this end, we used an immersive virtual environment where we induced embodiment of a virtual arm that was co-located with the real one and seen from a first person perspective. Virtual reality allowed us to dynamically modify the colour of the skin of the virtual arm. In order to test pain threshold, increasing ramps of heat stimulation applied on the participants’ arm were delivered concomitantly with the gradual intensification of different colours on the embodied avatar’s arm. We found that a reddened arm significantly decreased the pain threshold compared with normal and bluish coloured skin. This effect was specific when red was seen in the arm, while seeing red in a spot outside the arm did not decrease pain threshold. These results demonstrate an influence of skin colour on pain perception. This top-down modulation of pain through visual input suggests a potential use of embodied virtual bodies for pain therapy.

  9. Echography of young stars reveals their evolution

    CERN Document Server

    Zwintz, K; Ryabchikova, T; Guenther, D; Aerts, C; Barnes, T G; Themessl, N; Lorenz, D; Cameron, C; Kuschnig, R; Pollack-Drs, S; Moravveji, E; Baglin, A; Matthews, J M; Moffat, A F J; Poretti, E; Rainer, M; Rucinski, S M; Sasselov, D; Weiss, W W

    2014-01-01

    We demonstrate that a seismic analysis of stars in their earliest evolutionary phases is a powerful method to identify young stars and distinguish their evolutionary states. The early star that is born from the gravitational collapse of a molecular cloud reaches at some point sufficient temperature, mass and luminosity to be detected. Accretion stops and the pre-main sequence star that emerges is nearly fully convective and chemically homogeneous. It will continue to contract gravitationally until the density and temperature in the core are high enough to start nuclear burning of hydrogen. We show that there is a relationship between detected pulsation properties for a sample of young stars and their evolutionary status illustrating the potential of asteroseismology for the early evolutionary phases.

  10. Assessing the Exceptionality of Coloured Motifs in Networks

    Directory of Open Access Journals (Sweden)

    Lacroix Vincent

    2009-01-01

    Full Text Available Various methods have been recently employed to characterise the structure of biological networks. In particular, the concept of network motif and the related one of coloured motif have proven useful to model the notion of a functional/evolutionary building block. However, algorithms that enumerate all the motifs of a network may produce a very large output, and methods to decide which motifs should be selected for downstream analysis are needed. A widely used method is to assess if the motif is exceptional, that is, over- or under-represented with respect to a null hypothesis. Much effort has been put in the last thirty years to derive -values for the frequencies of topological motifs, that is, fixed subgraphs. They rely either on (compound Poisson and Gaussian approximations for the motif count distribution in Erdös-Rényi random graphs or on simulations in other models. We focus on a different definition of graph motifs that corresponds to coloured motifs. A coloured motif is a connected subgraph with fixed vertex colours but unspecified topology. Our work is the first analytical attempt to assess the exceptionality of coloured motifs in networks without any simulation. We first establish analytical formulae for the mean and the variance of the count of a coloured motif in an Erdös-Rényi random graph model. Using simulations under this model, we further show that a Pólya-Aeppli distribution better approximates the distribution of the motif count compared to Gaussian or Poisson distributions. The Pólya-Aeppli distribution, and more generally the compound Poisson distributions, are indeed well designed to model counts of clumping events. Altogether, these results enable to derive a -value for a coloured motif, without spending time on simulations.

  11. Accretion Discs Show Their True Colours

    Science.gov (United States)

    2008-07-01

    Quasars are the brilliant cores of remote galaxies, at the hearts of which lie supermassive black holes that can generate enough power to outshine the Sun a trillion times. These mighty power sources are fuelled by interstellar gas, thought to be sucked into the hole from a surrounding 'accretion disc'. A paper in this week's issue of the journal Nature, partly based on observations collected with ESO's Very Large Telescope, verifies a long-standing prediction about the intensely luminous radiation emitted by these accretion discs. Uncovering the disc ESO PR Photo 21/08 Uncovering the inner disc "Astronomers were puzzled by the fact that the best models of these discs couldn't quite be reconciled with some of the observations, in particular, with the fact that these discs did not appear as blue as they should be," explains lead-author Makoto Kishimoto. Such a discrepancy could be the signal that there was something very wrong with the models. With his colleagues, he investigated this discrepancy by studying the polarised light from six quasars. This enabled them to demonstrate that the disc spectrum is as blue as predicted. "The crucial observational difficulty here has been that the disc is surrounded by a much larger torus containing hot dust, whose light partly outshines that of the disc," says Kishimoto. "Because the light coming from the disc is scattered in the disc vicinity and thus polarised, by observing only polarised light from the quasars, one can uncover the buried light from the disc." In a similar way that a fisherman would wear polarised sunglasses to help get rid of the glare from the water surface and allow him to see more clearly under the water, the filter on the telescope allowed the astronomers to see beyond surrounding clouds of dust and gas to the blue colour of the disc in infrared light. The observations were done with the FORS and ISAAC instruments on one of the 8.2-m Unit Telescopes of ESO's Very Large Telescope, located in the Atacama

  12. Robust colour constancy in red-green dichromats.

    Science.gov (United States)

    Álvaro, Leticia; Linhares, João M M; Moreira, Humberto; Lillo, Julio; Nascimento, Sérgio M C

    2017-01-01

    Colour discrimination has been widely studied in red-green (R-G) dichromats but the extent to which their colour constancy is affected remains unclear. This work estimated the extent of colour constancy for four normal trichromatic observers and seven R-G dichromats when viewing natural scenes under simulated daylight illuminants. Hyperspectral imaging data from natural scenes were used to generate the stimuli on a calibrated CRT display. In experiment 1, observers viewed a reference scene illuminated by daylight with a correlated colour temperature (CCT) of 6700K; observers then viewed sequentially two versions of the same scene, one illuminated by either a higher or lower CCT (condition 1, pure CCT change with constant luminance) or a higher or lower average luminance (condition 2, pure luminance change with a constant CCT). The observers' task was to identify the version of the scene that looked different from the reference scene. Thresholds for detecting a pure CCT change or a pure luminance change were estimated, and it was found that those for R-G dichromats were marginally higher than for normal trichromats regarding CCT. In experiment 2, observers viewed sequentially a reference scene and a comparison scene with a CCT change or a luminance change above threshold for each observer. The observers' task was to identify whether or not the change was an intensity change. No significant differences were found between the responses of normal trichromats and dichromats. These data suggest robust colour constancy mechanisms along daylight locus in R-G dichromacy.

  13. Weaves and Colours of Lithuanian Folk Skirts Fabrics

    Directory of Open Access Journals (Sweden)

    Eglė KUMPIKAITĖ

    2013-09-01

    Full Text Available In the article weaves and colours of Lithuanian folk skirts fabrics are analysed. The investigation objects are the skirts from funds of three Lithuanian Museums: 258 skirts from National M. K. Čiurlionis Museum of Art, 85 skirts from Lithuanian Open Air Museum and 16 skirts from A. and A. Tamošaitis gallery “Židinys”. Distribution of skirts fabrics according to weaves was estimated, and it shows, that fabrics of plain weave are most widespread (53 %, combined and twill weaves are less popular (19 % and 18 %, respectively. The weaves of fabrics are determined during investigation and plans of weave were made proposing recommendations for manufacturing of similar fabrics. Also distribution of colours and number of colours in the fabrics were analysed. The biggest number of colours is in fabrics of simple weaves (plain and twill, and the most characteristic are green, red, black and blue colours. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.5240

  14. Capture by colour: evidence for dimension-specific singleton capture.

    Science.gov (United States)

    Harris, Anthony M; Becker, Stefanie I; Remington, Roger W

    2015-10-01

    Previous work on attentional capture has shown the attentional system to be quite flexible in the stimulus properties it can be set to respond to. Several different attentional "modes" have been identified. Feature search mode allows attention to be set for specific features of a target (e.g., red). Singleton detection mode sets attention to respond to any discrepant item ("singleton") in the display. Relational search sets attention for the relative properties of the target in relation to the distractors (e.g., redder, larger). Recently, a new attentional mode was proposed that sets attention to respond to any singleton within a particular feature dimension (e.g., colour; Folk & Anderson, 2010). We tested this proposal against the predictions of previously established attentional modes. In a spatial cueing paradigm, participants searched for a colour target that was randomly either red or green. The nature of the attentional control setting was probed by presenting an irrelevant singleton cue prior to the target display and assessing whether it attracted attention. In all experiments, the cues were red, green, blue, or a white stimulus rapidly rotated (motion cue). The results of three experiments support the existence of a "colour singleton set," finding that all colour cues captured attention strongly, while motion cues captured attention only weakly or not at all. Notably, we also found that capture by motion cues in search for colour targets was moderated by their frequency; rare motion cues captured attention (weakly), while frequent motion cues did not.

  15. Class Separation Improvements in Pixel Classification Using Colour Injection

    Science.gov (United States)

    Blanco, Edward; Mazo, Manuel; Bergasa, Luis; Palazuelos, Sira; Rodríguez, Jose; Losada, Cristina; Martín, Jose

    2010-01-01

    This paper presents an improvement in the colour image segmentation in the Hue Saturation (HS) sub-space. The authors propose to inject (add) a colour vector in the Red Green Blue (RGB) space to increase the class separation in the HS plane. The goal of the work is the development of an algorithm to obtain the optimal colour vector for injection that maximizes the separation between the classes in the HS plane. The chromatic Chrominace-1 Chrominance-2 sub-space (of the Luminance Chrominace-1 Chrominance-2 (YC1C2) space) is used to obtain the optimal vector to add. The proposal is applied on each frame of a colour image sequence in real-time. It has been tested in applications with reduced contrast between the colours of the background and the object, and particularly when the size of the object is very small in comparison with the size of the captured scene. Numerous tests have confirmed that this proposal improves the segmentation process, considerably reducing the effects of the variation of the light intensity of the scene. Several tests have been made in skin segmentation in applications for sign language recognition via computer vision, where an accurate segmentation of hands and face is required. PMID:22163628

  16. How hollow melanosomes affect iridescent colour production in birds.

    Science.gov (United States)

    Eliason, Chad M; Bitton, Pierre-Paul; Shawkey, Matthew D

    2013-09-22

    Developmental constraints and trade-offs can limit diversity, but organisms have repeatedly evolved morphological innovations that overcome these limits by expanding the range and functionality of traits. Iridescent colours in birds are commonly produced by melanin-containing organelles (melanosomes) organized into nanostructured arrays within feather barbules. Variation in array type (e.g. multilayers and photonic crystals, PCs) is known to have remarkable effects on plumage colour, but the optical consequences of variation in melanosome shape remain poorly understood. Here, we used a combination of spectrophotometric, experimental and theoretical methods to test how melanosome hollowness--a morphological innovation largely restricted to birds--affects feather colour. Optical analyses of hexagonal close-packed arrays of hollow melanosomes in two species, wild turkeys (Meleagris gallopavo) and violet-backed starlings (Cinnyricinclus leucogaster), indicated that they function as two-dimensional PCs. Incorporation of a larger dataset and optical modelling showed that, compared with solid melanosomes, hollow melanosomes allow birds to produce distinct colours with the same energetically favourable, close-packed configurations. These data suggest that a morphological novelty has, at least in part, allowed birds to achieve their vast morphological and colour diversity.

  17. EFFECT OF STEAMING ON THE COLOUR CHANGE OF SOFTWOODS

    Directory of Open Access Journals (Sweden)

    Laszlo Tolvaj,

    2012-05-01

    Full Text Available The heat treatment of softwood (i.e. spruce, pine, fir, and larch may result in significant colour changes. During this study Scots pine and spruce samples were steamed and analysed for their altered hue and lightness. Treatments included: 0 to 22 days of steaming time at a temperature range of 70 to 100°C. The outcome included a variety of colours between the initial hues and brownish tint. These new colours are similar to that of aged furniture and indoor wooden structures. Consequently, properly steamed softwood may be used to repair historical artefacts and relic furniture. Besides restoration, steamed stocks are excellent sources for manufacture of periodical furniture, where the aged appearance has aesthetical value. Results however, indicated that steaming at a temperature above 90 ˚C has a bleaching effect, i.e. the coloured chemical components formed by moderate steaming may be removed. Furthermore, we observed a linear correlation between lightness and colour hue at all steaming times and temperatures.

  18. Spectral response data for development of cool coloured tile coverings

    Science.gov (United States)

    Libbra, Antonio; Tarozzi, Luca; Muscio, Alberto; Corticelli, Mauro A.

    2011-03-01

    Most ancient or traditional buildings in Italy show steep-slope roofs covered by red clay tiles. As the rooms immediately below the roof are often inhabited in historical or densely urbanized centres, the combination of low solar reflectance of tile coverings and low thermal inertia of either wooden roof structures or sub-tile insulation panels makes summer overheating a major problem. The problem can be mitigated by using tiles coated with cool colours, that is colours with the same spectral response of clay tiles in the visible, but highly reflecting in the near infrared range, which includes more than half of solar radiation. Cool colours can yield the same visible aspect of common building surfaces, but higher solar reflectance. Studies aimed at developing cool colour tile coverings for traditional Italian buildings have been started. A few coating solutions with the typical red terracotta colour have been produced and tested in the laboratory, using easily available materials. The spectral response and the solar reflectance have been measured and compared with that of standard tiles.

  19. Class Separation Improvements in Pixel Classification Using Colour Injection

    Directory of Open Access Journals (Sweden)

    Jose Martín

    2010-08-01

    Full Text Available This paper presents an improvement in the colour image segmentation in the Hue Saturation (HS sub-space. The authors propose to inject (add a colour vector in the Red Green Blue (RGB space to increase the class separation in the HS plane. The goal of the work is the development of an algorithm to obtain the optimal colour vector for injection that maximizes the separation between the classes in the HS plane. The chromatic Chrominace-1 Chrominance-2 sub-space (of the Luminance Chrominace-1 Chrominance-2 (YC1C2 space is used to obtain the optimal vector to add. The proposal is applied on each frame of a colour image sequence in real-time. It has been tested in applications with reduced contrast between the colours of the background and the object, and particularly when the size of the object is very small in comparison with the size of the captured scene. Numerous tests have confirmed that this proposal improves the segmentation process, considerably reducing the effects of the variation of the light intensity of the scene. Several tests have been made in skin segmentation in applications for sign language recognition via computer vision, where an accurate segmentation of hands and face is required.

  20. Investigation into the Accuracy of Colours Reproduced by the Ricoh Printer

    Directory of Open Access Journals (Sweden)

    Andrius Gedvila

    2013-02-01

    Full Text Available The paper investigates the reproduction accuracy of Ricoh Aficio colour 3006 printer. The study has been conducted analyzing four-color (CMYK gradation curves – the compliance of zonal absorbance with standard references and printing stability of gradation scales. The obtained colours have been measured spectrophotometrically determining the coordinates of colours CIE L*a*b* and differences in colours ΔE. Eight printing regimes and their settings have been examined. It has been found that the printer Ricoh has inaccurately colour grading. However, the quality of colour reproduction is sufficient for printing data not requiring high accuracy of colour reproduction. Colour grading significantly differs from the theoretical approaches, though some regimes (Gamma, Brightness, CMYK simulation allows achieving theoretical values. Despite the high inaccuracy of gradation, differences in colour are not high enough due to corrections made by software.Article in Lithuanian

  1. Background matching and evolution of cryptic colours of selected passerines in deciduous woodlands

    DEFF Research Database (Denmark)

    Bursell, Jens; Dyck, Jan

    2003-01-01

    colours of tits and associated species with colour backgrounds in their habitat during a four-month period in winter. We test the hypothesis that in some of the species back colour is similar to one of the background colours. In addition to colour backgrounds, microhabitats and tree species were also...... recorded. Great Tit Parus major, Nuthatch Sitta europea and Treecreeper Certhia familiaris showed distinct preferences for different colour backgrounds, reflecting their choice of microhabitats and tree species. The data suggest that in the Great Tit the olivemoss green back colour has evolved as crypsis...... brown- greyish brown bark surfaces. The possibility that the grey back colour of the Marsh Tit Parus palustris has evolved as crypsis against greyish branches is discussed. For the Blue Tit Parus caeruleus it is suggested that the green back colour has evolved as crypsis against leaves during summer...

  2. Modelling colour constancy in fish: implications for vision and signalling in water.

    Science.gov (United States)

    Wilkins, Lucas; Marshall, N Justin; Johnsen, Sönke; Osorio, D

    2016-06-15

    Colour vision and colour signals are important to aquatic animals, but light scattering and absorption by water distorts spectral stimuli. To investigate the performance of colour vision in water, and to suggest how photoreceptor spectral sensitivities and body colours might evolve for visual communication, we model the effects of changes in viewing distance and depth on the appearance of fish colours for three teleosts: a barracuda, Sphyraena helleri, which is dichromatic and two damselfishes, Chromis verater and Chromis hanui, which are trichromatic. We assume that photoreceptors light-adapt to the background, thereby implementing the von Kries transformation, which can largely account for observed colour constancy in humans and other animals, including fish. This transformation does not, however, compensate for light scattering over variable viewing distances, which in less than a metre seriously impairs dichromatic colour vision, and makes judgement of colour saturation unreliable for trichromats. The von Kries transformation does substantially offset colour shifts caused by changing depth, so that from depths of 0 to 30 m modelled colour changes (i.e. failures of colour constancy) are sometimes negligible. However, the magnitudes and directions of remaining changes are complex, depending upon the specific spectral sensitivities of the receptors and the reflectance spectra. This predicts that when judgement of colour is important, the spectra of signalling colours and photoreceptor spectral sensitivities should be evolutionarily linked, with the colours dependent on photoreceptor spectral sensitivities, and vice versa.

  3. Computer aided method for colour calibration and analysis of digital rock photographs

    Directory of Open Access Journals (Sweden)

    Matic Potočnik

    2015-12-01

    Full Text Available The methods used in geology to determine colour and colour coverage are expensive, time consuming, and/ or subjective. Estimates of colour coverage can only be approximate since they are based on rough comparisonbased measuring etalons and subjective estimation, which is dependent upon the skill and experience of the person performing the estimation. We present a method which accelerates, simplifis, and objectifis these tasks using a computer application. It automatically calibrates the colours of a digital photo, and enables the user to read colour values and coverage, even after returning from fild work. Colour identifiation is based on the Munsell colour system. For the purposes of colour calibration we use the X-Rite ColorChecker Passport colour chart placed onto the photographed scene. Our computer application detects the ColorChecker colour chart, and fids a colour space transformation to calibrate the colour in the photo. The user can then use the application to read colours within selected points or regions of the photo. The results of the computerised colour calibration were compared to the reference values of the ColorChecker chart. The values slightly deviate from the exact values, but the deviation is around the limit of human capability for visual comparison. We have devised an experiment, which compares the precision of the computerised colour analysis and manual colour analysis performed on a variety of rock samples with the help of geology students using Munsell Rock-color Chart. The analysis showed that the precision of manual comparative identifiation on multicoloured samples is somewhat problematic, since the choice of representative colours and observation points for a certain part of a sample are subjective. The computer based method has the edge in verifibility and repeatability of the analysis since the application the original photo to be saved with colour calibration, and tagging of colouranalysed points and regions.

  4. Assessing SNPs in coat colour genes for cattle breed traceability

    Directory of Open Access Journals (Sweden)

    Paola Crepaldi

    2010-01-01

    Full Text Available Aim of this research was to identify a panel of SNPs in coat colour genes useful for breed traceability in Rendena, an autochthonous cattle breed raised in the province of Trento, and other 4 Italian cattle breeds. First, we sequenced some regions of several coat colour genes in 10 animals belonging to 5 breeds characterised by different coat colour phenotypes (Rendena, Italian Brown, Grey Alpine, Italian Friesian, and Italian Red Pied, and we detected 21 SNPs in 13 genes. These markers and 6 additional SNPs were used to genotype 180 animals of the same 5 breeds obtaining useful genotyping data for a total of 22 SNPs in 13 genes. Five out of the 22 SNP markers in the MC1R, KIT, MLPH, and SILV genes had the highest discriminating power. The panel of 22 SNPs is useful to trace Rendena particularly from Red Italian Pied and Italian Friesian.

  5. CLINICAL EVALUATION OF SELECTED COLOURING HERBALS IN SAVARNIKARAN

    Directory of Open Access Journals (Sweden)

    Wadikar Sujata Surendra

    2013-03-01

    Full Text Available A Clinical study on "Clinical Evaluation of Selected Colouring Herbals in Savarnikaran" was carried out at shalya tantra dept. of M.A.Podar Hospital, Worli, Mumbai 18. The prime aim of the study is to make available an effective, alternative colouring cosmetic preparations which will be useful in post burn, post acne and post wound colour morbidity.Ayurvedic herbal drugs are abundant, easily available and cost effective but their use is not observed in all forms. The trial drug is prepared in powder-paste, oil and ointment form. Further the efficacy of the different preparation is also evaluated separately. Cosmetic aspect of ayurvedic surgery is neglected, here we attempt to bring this aspect in routine practice.Total number of 40 patients were studied in this clinical study.Observations were documented through specially designed clinical record form and relevant conclusions were drawn.

  6. Global warming favours light-coloured insects in Europe.

    Science.gov (United States)

    Zeuss, Dirk; Brandl, Roland; Brändle, Martin; Rahbek, Carsten; Brunzel, Stefan

    2014-05-27

    Associations between biological traits of animals and climate are well documented by physiological and local-scale studies. However, whether an ecophysiological phenomenon can affect large-scale biogeographical patterns of insects is largely unknown. Insects absorb energy from the sun to become mobile, and their colouration varies depending on the prevailing climate where they live. Here we show, using data of 473 European butterfly and dragonfly species, that dark-coloured insect species are favoured in cooler climates and light-coloured species in warmer climates. By comparing distribution maps of dragonflies from 1988 and 2006, we provide support for a mechanistic link between climate, functional traits and species that affects geographical distributions even at continental scales. Our results constitute a foundation for better forecasting the effect of climate change on many insect groups.

  7. Genes controlling mimetic colour pattern variation in butterflies.

    Science.gov (United States)

    Nadeau, Nicola J

    2016-10-01

    Butterfly wing patterns are made up of arrays of coloured scales. There are two genera in which within-species variation in wing patterning is common and has been investigated at the molecular level, Heliconius and Papilio. Both of these species have mimetic relationships with other butterfly species that increase their protection from predators. Heliconius have a 'tool-kit' of five genetic loci that control colour pattern, three of which have been identified at the gene level, and which have been repeatedly used to modify colour pattern by different species in the genus. By contrast, the three Papilio species that have been investigated each have different genetic mechanisms controlling their polymorphic wing patterns.

  8. COLOUR CHARACTESISTICS OF PINE WOOD AFFECTED BY TERMAL COMPRESSING

    Directory of Open Access Journals (Sweden)

    Celil Atik

    2013-06-01

    Full Text Available http://dx.doi.org/10.5902/198050989291The goal of this study was to determine the effects of thermal modification and hot-pressing on the colour characteristics of pine wood as bio-resource. The experimental wood boards with dimensions of 250 mm in width by 500 mm in length by 18 mm in thickness were thermally compressed at a temperature of 120˚C or 150˚C, press pressure of 5 or 7 MPa for 60 min in a hot press. Results obtained in this study showed that the colour characteristics of the pine wood boards were affected by press pressure and temperature. The resin leakages significantly increased the chromacity (a* - 25.99 and b* - 43.18 of the treated wood samples. Thermally compressing caused browning of wood colour, which rate increases with pressure at high temperature conditions.

  9. Colour based fire detection method with temporal intensity variation filtration

    Science.gov (United States)

    Trambitckii, K.; Anding, K.; Musalimov, V.; Linß, G.

    2015-02-01

    Development of video, computing technologies and computer vision gives a possibility of automatic fire detection on video information. Under that project different algorithms was implemented to find more efficient way of fire detection. In that article colour based fire detection algorithm is described. But it is not enough to use only colour information to detect fire properly. The main reason of this is that in the shooting conditions may be a lot of things having colour similar to fire. A temporary intensity variation of pixels is used to separate them from the fire. These variations are averaged over the series of several frames. This algorithm shows robust work and was realised as a computer program by using of the OpenCV library.

  10. A Note on Lower Bounds for Colourful Simplicial Depth

    Directory of Open Access Journals (Sweden)

    Antoine Deza

    2013-01-01

    Full Text Available The colourful simplicial depth problem in dimension d is to find a configuration of (d+1 sets of (d+1 points such that the origin is contained in the convex hull of each set, or colour, but contained in a minimal number of colourful simplices generated by taking one point from each set. A construction attaining d2 + 1 simplices is known, and is conjectured to be minimal. This has been confirmed up to d = 3, however the best known lower bound for d ≥ 4 is ⌈(d+12 /2 ⌉. In this note, we use a branching strategy to improve the lower bound in dimension 4 from 13 to 14.

  11. Segregated Optical-NIR colour distributions of MDS galaxies

    CERN Document Server

    Ferreras, I; Martínez-González, E; Benítez, N

    1998-01-01

    We present a K survey of 29 fields covering approximately 90 arcmin^2 from the Medium Deep Survey (MDS) catalogue down to a completeness magnitude of K=18.0 (limiting magnitude K=19.0). The morphology obtained by the MDS team using high resolution images from HST/WFPC2 along with our NIR observations allow a Colour-Magnitude and Colour-Colour analysis that agrees in general with spectral evolution models (Bruzual & Charlot 1998) especially if a reasonable range of metallicities for the Simple Stellar Populations used (0.2 4.5, setting an upper limit to the number density of EROs at dn_{EROs}/dØmega < 0.011 arcmin^{-2} (K < 18.0).

  12. Measurement of Colour on Translucent Material Viewed by Reflection

    Directory of Open Access Journals (Sweden)

    Aditya Sole

    2007-11-01

    Full Text Available In this paper a measurement technique is developed to measure colour printed on translucent media with reflection mode geometry with a backing material. A number of paper backing materials along with PTFE plaque tiles of 10 mm and 6 mm thickness are investigated for conformation with ISO/CD 13655 (2006 and CGATS (2001 standards for backing materials. A measurement procedure is developed using these backing materials to make measurements relative to perfect diffuser. A model is also developed to predict CIE XYZ tri-stimulus values of a colour patch to be printed on paper to match with the same colour patch printed on translucent substrate viewed by reflection with a GMG double backing proofing paper. This model is then evaluated psychophysically using a halftone print. Categorical judgement technique is used to collect visual data.

  13. Modified Karhunen-Loéve expansion for evaluating skin-colour-associated melanoma risk factors.

    Science.gov (United States)

    Cevenini, G; Borzelli, G; Rubegni, P; Massai, M R; Andreassi, L; Barbini, P

    2000-07-01

    An approach based on the modified Karhunen-Loéve expansion (MKLE) of constitutive and facultative skin colour data acquired by colorimeters in melanoma patients and healthy control subjects, was used to identify two colour features defining skin-colour-associated risk of melanoma. None of four common statistical classifiers trained on colour features were sufficiently accurate for allowing skin colour alone to be used for classification purposes, though a Bayesian quadratic classifier matched the transformed data well. This study supersedes the indeterminate character of most common clinical criteria based on qualitative factors and, irrespective of the results of classification, provides objective skin colour information for the prevention of melanoma.

  14. Gamut Volume Index: a color preference metric based on meta-analysis and optimized colour samples.

    Science.gov (United States)

    Liu, Qiang; Huang, Zheng; Xiao, Kaida; Pointer, Michael R; Westland, Stephen; Luo, M Ronnier

    2017-07-10

    A novel metric named Gamut Volume Index (GVI) is proposed for evaluating the colour preference of lighting. This metric is based on the absolute gamut volume of optimized colour samples. The optimal colour set of the proposed metric was obtained by optimizing the weighted average correlation between the metric predictions and the subjective ratings for 8 psychophysical studies. The performance of 20 typical colour metrics was also investigated, which included colour difference based metrics, gamut based metrics, memory based metrics as well as combined metrics. It was found that the proposed GVI outperformed the existing counterparts, especially for the conditions where correlated colour temperatures differed.

  15. A study of women heterozygous for colour deficiencies.

    Science.gov (United States)

    Jordan, G; Mollon, J D

    1993-07-01

    We have examined the colour vision of 43 female subjects in the age range 30-59 yr of whom 31 were obligate carriers of various forms of colour deficiency and the rest were women who had no known colour-deficient relatives. In the case of all the carriers we established the phenotypes of their colour-deficient sons. As a group, carriers made significantly more errors on the Ishihara plates and showed enlarged matching ranges on the Nagel anomaloscope, but we could not replicate earlier reports of increased error scores on the Farnsworth-Munsell 100-Hue test or of systematic shifts in Rayleigh match mid-points. We did find that the colour matches of carriers of deuteranomaly were significantly displaced from those of normals in a ratio-matching task in which a mixture of 546 and 600 nm was matched with a mixture of 570 and 690 nm. Owing to X-chromosome inactivation, women who are heterozygous for anomalous trichromacy ought to have at least four types of cone in their retinae and we ask whether this affords them an extra dimension of colour vision, by analogy to New World monkeys where heterozygous females gain trichromacy in a basically dichromatic species. Many carriers of anomalous trichromacy exhibited no evidence for tetrachromacy, in that they accepted large-field Rayleigh matches following a rod bleach and they were unable to set unique matches in our ratio-matching task. However, eight carriers of anomalous trichromacy--and no other subject--refused large-field Rayleigh matches; and we found one carrier of deuteranomaly who was apparently able to make unique matches in the ratio-matching task.

  16. Regional ocean-colour chlorophyll algorithms for the Red Sea

    KAUST Repository

    Brewin, Robert J.W.

    2015-05-18

    The Red Sea is a semi-enclosed tropical marine ecosystem that stretches from the Gulf of Suez and Gulf of Aqaba in the north, to the Gulf of Aden in the south. Despite its ecological and economic importance, its biological environment is relatively unexplored. Satellite ocean-colour estimates of chlorophyll concentration (an index of phytoplankton biomass) offer an observational platform to monitor the health of the Red Sea. However, little is known about the optical properties of the region. In this paper, we investigate the optical properties of the Red Sea in the context of satellite ocean-colour estimates of chlorophyll concentration. Making use of a new merged ocean-colour product, from the European Space Agency (ESA) Climate Change Initiative, and in situ data in the region, we test the performance of a series of ocean-colour chlorophyll algorithms. We find that standard algorithms systematically overestimate chlorophyll when compared with the in situ data. To investigate this bias we develop an ocean-colour model for the Red Sea, parameterised to data collected during the Tara Oceans expedition, that estimates remote-sensing reflectance as a function of chlorophyll concentration. We used the Red Sea model to tune the standard chlorophyll algorithms and the overestimation in chlorophyll originally observed was corrected. Results suggest that the overestimation was likely due to an excess of CDOM absorption per unit chlorophyll in the Red Sea when compared with average global conditions. However, we recognise that additional information is required to test the influence of other potential sources of the overestimation, such as aeolian dust, and we discuss uncertainties in the datasets used. We present a series of regional chlorophyll algorithms for the Red Sea, designed for a suite of ocean-colour sensors, that may be used for further testing.

  17. Analysis of Wilhelm Ostwald's "Colour Organ" with Raman microspectroscopy

    Science.gov (United States)

    Bridarolli, Alexandra; Atak, Sefkan; Herm, Christoph

    2016-11-01

    The "Scientific Colour Organ" is a collection of 680 pigment powders, created by the chemist Wilhelm Ostwald in 1925 as a means to represent his colour system. Today, it remains a leading part of colour theory. Analysis of these materials was undertaken to understand how the colour system was realised and to gain indications for preservation of the collection to which it belongs. Dispersive Raman microspectroscopy was applied directly to the powders, as well as using alternative techniques to suppress fluorescence. Barium sulphate was detected in all of the samples with one exception. Portable X-ray fluorescence revealed that this compound was a constituent of lithopone pigment. Raman spectroscopy furthermore revealed synthetic ultramarine (C.I. PB 29) as well as six different synthetic organic pigments and dyes (C.I. PY3; C.I. PO5; C.I. PR81:1; C.I. PV2 and two different triarylmethane dyes). Thin-layer chromatography was applied to determine the exact combination of dyes causing the gradual change in colour of each powder compared to the adjacent samples. With the exception of triarylmethane, the synthetic organic dyes could be identified with Raman spectroscopy directly on the chromatographic plate. The efficiency of thin-layer chromatography combined with Raman spectroscopy for identification of organic pigments could thus be shown. X-ray fluorescence indicated the presence of tungsten-molybdenum lakes in some samples. Comparison of the analytical results to information published by Oswald in 1917 showed that he switched to more light-stable synthetic organic pigments used for his "Scientific Colour Organ".

  18. Medical Gas Cylinder with Mismatched Colour and Pin Index

    Directory of Open Access Journals (Sweden)

    Mukherjee S

    2014-08-01

    Full Text Available The medical gas cylinders have various safety features to prevent the administration of wrong gas to the patient. Most of the features have visual impact (colour, label, markings on the cylinder body except pin index system on the cylinder valve, so error in this feature is difficult to analyze and is highly unpredictable. We had received one such cylinder in our institution where all other features (label, colour, marking pointed to nitrous oxide except the pin index which resembled with that of oxygen

  19. The colour red affects time perception differently in different contexts.

    Science.gov (United States)

    Shi, Jiaxin; Huang, Xiting

    2017-02-01

    Previous studies have found that psychological and behavioural functions of the colour red vary according to context. In this research, we used the verbal estimation paradigm to determine if the colour red affects individuals' perception of interval duration. In our results, perceived duration was shorter in a red condition than in a blue one; additionally, only in the red condition, perceived duration was shorter in an online dating context than in an online interviewing context. The contribution and limitations of this study and future research directions are discussed. © 2016 International Union of Psychological Science.

  20. Hemifield dependence of responses to colour in human fusiform gyrus.

    Science.gov (United States)

    Gonzalez, Francisco; Relova, José Luis; Prieto, Angel; Peleteiro, Manuel; Romero, Maria C

    2006-08-01

    To investigate the hemifield dependence of visually evoked responses to colour in the human fusiform gyrus we recorded evoked potentials from subdural electrodes in a patient suffering from occipital epilepsy. The responses in the fusiform gyrus show a strong hemifield dependence and discriminate the onset from the offset of the stimulus. Additionally, we found responses to squares made of random dots, whereas no responses were found to squares with a homogeneous bright surface. Our findings further support the idea that the fusiform gyrus is related to colour and pattern perception. However, the hemifield dependence we found may indicate that further processing is required in order to combine information from both visual hemifields.

  1. 3-Colourability of Dually Chordal Graphs in Linear Time

    CERN Document Server

    Leitert, Arne

    2012-01-01

    A graph G is dually chordal if there is a spanning tree T of G such that any maximal clique of G induces a subtree in T. This paper investigates the Colourability problem on dually chordal graphs and will show that it is NP-complete in case of four colors. For 3-Colourability this paper will show that a dually chordal graph is 3-colorable if and only if it is perfect and has no clique of size four. Also a simple linear time algorithm is given to find a 3-coloring in a dually chordal graph.

  2. Pseudo natural colour aerial imagery for urban and suburban mapping

    DEFF Research Database (Denmark)

    Knudsen, Thomas

    2005-01-01

    Due to their near-infrared data channel, digital airborne four-channel imagers provide a potentially good discrimination between vegetation and human-made materials, which is very useful in automated mapping. Due to their red, green and blue data channels, they also provide natural colour images......, which are very useful in traditional (manual) mapping. In this paper, an algorithm is described which provides an approximation to the spectral capabilities of the four-channel imagers by using a colour-infrared aerial photo as input. The algorithm is tailored to urban/suburban surroundings, where...

  3. A new `hidden colour hypothesis' in hadron physics

    Indian Academy of Sciences (India)

    Afsar Abbas

    2006-05-01

    A new `hidden colour hypothesis' within the framework of QCD, as an extension of and in keeping with the spirit of the `colour singlet hypothesis' is hereby proposed. As such it should play a role in a consistent description of exotic hadrons, such as diquonia, pentaquarks, dibaryons etc. How these exotic hadrons are affected by this new hypothesis is discussed here. This new hypothesis suggests that the experimentalists may not be looking for single exotics but for composites of two or more of the same.

  4. Microcavity-embedded, colour-tuneable, transparent organic solar cells.

    Science.gov (United States)

    Chen, Yi-Hong; Chen, Chang-Wen; Huang, Zheng-Yu; Lin, Wei-Chieh; Lin, Li-Yen; Lin, Francis; Wong, Ken-Tsung; Lin, Hao-Wu

    2014-02-01

    In this work microcavity-capped colour-tuneable SMOSCs are evaluated. By adopting a microcavity-structured cathode with optical spacer layers of different thicknesses fabricated in a Ag/NPB/Ag structure, the transmission spectra of complete devices can be tuned over the entire visible-light region (400-750 nm). The fabricated semitransparent colour-tuneable solar cells show an average efficiency of 4.78% under 1-sun illumination. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Lessons from flower colour evolution on targets of selection.

    Science.gov (United States)

    Wessinger, Carolyn A; Rausher, Mark D

    2012-10-01

    The genetic basis of flower colour evolution provides a useful system to address the debate over the relative contribution of regulatory vs. functional mutations in evolution. The relative importance of these two categories depends on the type of flower colour transition and the genes involved in those transitions. These differences reflect differences in the degree of deleterious pleiotropy associated with functional inactivation of various anthocyanin pathway genes. Our findings illustrate how generalized statements regarding the contributions of regulatory and functional mutations to broad categories of traits, such as morphological vs. physiological, ignore differences among traits within categories and in doing so overlook important factors determining the relative importance of regulatory and functional mutations.

  6. Behavioural ecology: bees associate warmth with floral colour.

    Science.gov (United States)

    Dyer, Adrian G; Whitney, Heather M; Arnold, Sarah E J; Glover, Beverley J; Chittka, Lars

    2006-08-01

    Floral colour signals are used by pollinators as predictors of nutritional rewards, such as nectar. But as insect pollinators often need to invest energy to maintain their body temperature above the ambient temperature, floral heat might also be perceived as a reward. Here we show that bumblebees (Bombus terrestris) prefer to visit warmer flowers and that they can learn to use colour to predict floral temperature before landing. In what could be a widespread floral adaptation, plants may modulate their temperature to encourage pollinators to visit.

  7. The genetics of eye colours in an Italian population measured with an objective method for eye colour quantification

    DEFF Research Database (Denmark)

    Pietroni, C.; Andersen, J.D.; Johansen, P.

    2013-01-01

    in pigmentary genes. High resolution digital images of the participants’ eyes were taken and the iris region was successfully extracted with the use of the custom designed software Digital Iris Analysis Tool (DIAT) from 218 of the 230 (95%) images. The software counted the numbers of blue and brown pixels...... in the iris region and calculated a Pixel Index of the Eye (PIE-score) that described the eye colours quantitatively. The PIE-score ranged from _1 to 1 (brown to blue). We investigated the association of the PIE-scores extracted from the eye images with the genotypes of the 32 pigmentary SNPs. We observed......Brown and blue eye colours are primarily explained by the single nucleotide polymorphism (SNP) HERC2 rs12913832. However, the genetics of eye colours that appear to be neither blue nor brown are not well understood. In this study, 230 unrelated Italian individuals were typed for 32 SNP loci...

  8. Environmental and hormonal factors controlling reversible colour change in crab spiders.

    Science.gov (United States)

    Llandres, Ana L; Figon, Florent; Christidès, Jean-Philippe; Mandon, Nicole; Casas, Jérôme

    2013-10-15

    Habitat heterogeneity that occurs within an individual's lifetime may favour the evolution of reversible plasticity. Colour reversibility has many different functions in animals, such as thermoregulation, crypsis through background matching and social interactions. However, the mechanisms underlying reversible colour changes are yet to be thoroughly investigated. This study aims to determine the environmental and hormonal factors underlying morphological colour changes in Thomisus onustus crab spiders and the biochemical metabolites produced during these changes. We quantified the dynamics of colour changes over time: spiders were kept in yellow and white containers under natural light conditions and their colour was measured over 15 days using a spectrophotometer. We also characterised the chemical metabolites of spiders changing to a yellow colour using HPLC. Hormonal control of colour change was investigated by injecting 20-hydroxyecdysone (20E) into spiders. We found that background colouration was a major environmental factor responsible for colour change in crab spiders: individuals presented with white and yellow backgrounds changed to white and yellow colours, respectively. An ommochrome precursor, 3-OH-kynurenine, was the main pigment responsible for yellow colour. Spiders injected with 20E displayed a similar rate of change towards yellow colouration as spiders kept in yellow containers and exposed to natural sunlight. This study demonstrates novel hormonal manipulations that are capable of inducing reversible colour change.

  9. Output power spectrum of a single-mode laser driven by coloured pump and quantum noises with coloured correlation

    Institute of Scientific and Technical Information of China (English)

    Han Li-Bo; Cao Li; Wu Da-Jin

    2004-01-01

    By using the linear approximation method, the output power spectrum is calculated for a single-mode laser driven by coloured pump and quantum noises with coloured correlation. We have observed that the configuration of the output power spectrum is complicated: that is, it can be of single peak, two peaks or three peaks. The configurations of the power spectrum can be transformed from one into another by changing the cross-correlation time, the cross-correlation coefficient between the two noises, and pump noise intensity.

  10. Perception of colour in French and Russian linguistic cultures: a study based on phraseological units

    Directory of Open Access Journals (Sweden)

    Жанна Вячеславовна Кургузенкова

    2014-12-01

    Full Text Available This paper analyzes the cultural connotations of different colours in French and Russian linguistic culture. It focuses on phraseological units of the colours “red”, “white”, “black” and “green”.

  11. A METHOD FOR RECORDING AND VIEWING STEREOSCOPIC IMAGES IN COLOUR USING MULTICHROME FILTERS

    DEFF Research Database (Denmark)

    2000-01-01

    differences prescribed by the stereoscopic principle and supplementing the colour perception. For selecting the filters, the invention suggests an auxiliary test. For encoding the stereograms, the invention suggests a special process of channel separation and replacement. For colour correction...

  12. Colorimetric evaluation of iPhone apps for colour vision tests based on the Ishihara test

    National Research Council Canada - National Science Library

    Dain, Stephen J; AlMerdef, Ali

    2016-01-01

    ...) providing colour vision testing would appear as an option. In this study, the colorimetric characteristics of five available iPhone apps for colour vision testing are assessed as a prequel to possible clinical evaluation...

  13. Local and relational judgements of surface colour : constancy indices and discrimination performance

    NARCIS (Netherlands)

    Van Es, Just J.; Vladusich, Tony; Cornelissen, Frans W.

    2007-01-01

    Colour constancy is generally assumed to arise from a combination of perceptual constancy mechanisms operating to partially discount illumination changes and relational mechanisms involved in judging the colour relationships between object surfaces. Here we examined the characteristics of these mech

  14. AGN feedback drives the colour evolution of local galaxies

    CERN Document Server

    Shabala, Stanislav S; Silk, Joseph

    2011-01-01

    We investigate the effects of AGN feedback on the colour evolution of galaxies found in local (z<0.2) groups and clusters. Galaxies located within the lobes of powerful Fanaroff-Riley type II (edge-brightened) sources show much redder colours than neighbouring galaxies that are not spatially coincident with the radio source. By contrast, no similar effect is seen near Fanaroff-Riley type I (core-dominated) radio sources. We show that these colours are consistent with FR-IIs truncating star formation as the expanding bow shock overruns a galaxy. We examine a sample of clusters with no detectable radio emission and show that galaxy colours in these clusters carry an imprint of past AGN feedback. AGN activity in the low-redshift Universe is predominantly driven by low-luminosity radio sources with short duty cycles. Our results show that, despite their rarity, feedback from powerful radio sources is an important driver of galaxy evolution even in the local volume.

  15. Perceptibility and acceptability thresholds for colour differences in dentistry

    NARCIS (Netherlands)

    Khashayar, G.; Bain, P.A.; Salari, S.; Dozic, A.; Kleverlaan, C.J.; Feilzer, A.J.

    2014-01-01

    Introduction Data on acceptability (AT) and perceptibility thresholds (PT) for colour differences vary in dental literature. There is consensus that the determination of ΔE* is appropriate to define AT and PT, however there is no consensus regarding the values that should be used. The aim of this cl

  16. Massive Quark Propagator in the Colour-Superconducting Phase

    Institute of Scientific and Technical Information of China (English)

    黄梅; 庄鹏飞; 赵维勤

    2002-01-01

    A more general expression for the quark propagator including both chiral and diquark condensates has been derived by using energy projectors. This makes it possible to study the phase transition from the hadron phase to the colour-superconductivity phase in the moderate baryon density region by using the Feynman diagrammatic method or the Green function method.

  17. Science means business: medical imaging shows colour of money

    CERN Multimedia

    Macfie, Rebecca

    2007-01-01

    Doctors have used x-ray machines for 100 years, but they remain an imprecise and limited diagnostic tool. But a team of Canterbury University researchers is aiming to revolutionise medical x-ray technology with high-precision colour imaging. (1,5 page)

  18. An Introduction to the Practical Use of Coloured Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt

    1998-01-01

    The development of Coloured Petri Nets (CP-nets or CPN) has been driven by the desire to develop a modelling language - at the same time theoretically well-founded and versatile enough to be used in practice for systems of the size and complexity found in typical industrial projects. To achieve t...

  19. Exploring Gender Norms through the "Colour Blind" Initiative

    Science.gov (United States)

    Niblett, Blair; Potvin, Leigh

    2010-01-01

    Recently, the authors have been collecting data for a research project that explores secondary school boys' perceptions of masculinity. They spent a week in Leigh's grade 11 philosophy class discussing gender while observing and video recording students' perception for analysis. In their research, they used Colour Blind as a vehicle for unearthing…

  20. Multicolour interphase cytogenetics: 24 chromosome probes, 6 colours, 4 layers.

    Science.gov (United States)

    Ioannou, D; Meershoek, E J; Thornhill, A R; Ellis, M; Griffin, D K

    2011-01-01

    From the late 1980s onwards, the use of DNA probes to visualise sequences on individual chromosomes (fluorescent in-situ hybridisation - FISH) revolutionised the study of cytogenetics. Following single colour experiments, more fluorochromes were added, culminating in a 24 colour assay that could distinguish all human chromosomes. Interphase cytogenetics (the detection of chromosome copy number in interphase nuclei) soon followed, however 24 colour experiments are hampered for this application as mixing fluorochromes to produce secondary colours produces images that are not easily distinguishable from overlapping signals. This study reports the development and use of a novel protocol, new fast hybridising FISH probes, and a bespoke image capture system for the assessment of chromosome copy number in interphase nuclei. The multicolour probe sets can be used individually or in sequential hybridisation layers to assess ploidy of all 24 human chromosomes in the same nucleus. Applications of this technique are in the investigation of chromosome copy number and the assessment of nuclear organisation for a range of different cell types including human sperm, cancer cells and preimplantation embryos.

  1. CPN Tools for Editing, Simulating, and Analysing Coloured Petri Nets

    DEFF Research Database (Denmark)

    Ratzer, Anne Vinter; Wells, Lisa Marie; Lassen, Henry Michael

    2003-01-01

    CPN Tools is a tool for editing, simulating and analysing Coloured Petri Nets. The GUI is based on advanced interaction techniques, such as toolglasses, marking menus, and bi-manual interaction. Feedback facilities provide contextual error messages and indicate dependency relationships between net...

  2. Coloured Petri Net Refinement Specification and Correctness Proof with Coq

    Science.gov (United States)

    Choppy, Christine; Mayero, Micaela; Petrucci, Laure

    2009-01-01

    In this work, we address the formalisation of symmetric nets, a subclass of coloured Petri nets, refinement in COQ. We first provide a formalisation of the net models, and of their type refinement in COQ. Then the COQ proof assistant is used to prove the refinement correctness lemma. An example adapted from a protocol example illustrates our work.

  3. preliminary investigation of a colouring matter extract from sorghum ...

    African Journals Online (AJOL)

    Umar Ali

    2012-03-21

    Mar 21, 2012 ... to textiles coloured with natural dyes may be one or combination of factors ... used particularly for goat-skin leather in Nigeria, but also for mats, textiles, ... The solvent mixtures were placed in different solvent tanks with cover.

  4. Radial Excitations in the Global Colour Soliton Model

    Institute of Scientific and Technical Information of China (English)

    WANG Bin; LIU Yu-Xin

    2007-01-01

    @@ With the Munczek-Nemirovsky model of the effective gluon propagator in the global colour model, we study the radially excited solitons in which one quark is excited and the other two are at the ground state. The obtained masses of the two radial excitations are comparable with the experimental data.

  5. Perceptibility and acceptability thresholds for colour differences in dentistry

    NARCIS (Netherlands)

    Khashayar, G.; Bain, P.A.; Salari, S.; Dozic, A.; Kleverlaan, C.J.; Feilzer, A.J.

    2014-01-01

    Introduction Data on acceptability (AT) and perceptibility thresholds (PT) for colour differences vary in dental literature. There is consensus that the determination of ΔE* is appropriate to define AT and PT, however there is no consensus regarding the values that should be used. The aim of this

  6. Influence of Colour on Acquisition and Generalisation of Graphic Symbols

    Science.gov (United States)

    Hetzroni, O. E.; Ne'eman, A.

    2013-01-01

    Background: Children with autism may benefit from using graphic symbols for their communication, language and literacy development. The purpose of this study was to investigate the influence of colour versus grey-scale displays on the identification of graphic symbols using a computer-based intervention. Method: An alternating treatment design was…

  7. Multiple Primary LED Lamp Colour Controller with Inherent Brightness Limitation

    NARCIS (Netherlands)

    Barcena, R.; Ackermann, B.

    2007-01-01

    There is a strong interest in using LEDs for general illumination due to the potential they offer for energy saving, environmental friendliness, new opportunities in lighting design, and control of the intensity, colour, and spatial distribution of light. General illumination requires primarily whit

  8. Advances in methods for colour marking of mosquitoes

    NARCIS (Netherlands)

    Verhulst, N.O.; Loonen, J.A.C.M.; Takken, W.

    2013-01-01

    Background: Different techniques are available for colour marking insects and each technique may be suitable for different insect species. Mosquitoes can be marked to determine population size, distribution and flight distance or distinguish closely related species. In this study, two methods of col

  9. Monitoring dental erosion by colour measurement : An in vitro study

    NARCIS (Netherlands)

    Krikken, J. B.; Zijp, J. R.; Huysmans, M. C. D. N. J. M.

    2008-01-01

    Objectives: The aim of this study was to develop a method to monitor dental erosion by evaluation of the colour change of teeth as a function of enamel loss, and to evaluate the reproducibility of the method used. Methods: Light reflectance spectra of 12 extracted human incisors were measured using

  10. Blue-Green Colour Categorisation in Mandarin-English Speakers

    Directory of Open Access Journals (Sweden)

    Emily Joanne Hird

    2012-05-01

    Full Text Available Observers are faster to detect a target among a set of distracters if the targets and distracters come from different colour categories. This cross-boundary advantage seems to be limited to the right visual field, which is consistent with the dominance of the left hemisphere for language processing. Here we study whether a similiar visual field advantage is found in Mandarin, a language which uses a logographic system. Forty late Mandarin-English bilinguals performed a blue-green colour categorisation task, in a blocked design, in their first language (L1: Mandarin or second language (L2: English. Eleven colour singletons ranging from blue to green were presented for 160ms, randomly in the left visual field (LVF or in the right visual field (RVF. We find that reaction times at the colour boundary were on average about 100 ms shorter in the LVF compared to the RVF, but only when the task was preformed in Mandarin as opposed to English. The apparent discrepancy with previous findings is conceivably due to the script nature of two languages: Mandarin logographic characters are analysed visuo-orthographically in the right fusiform gyrus [Guo and Burgund 2010, Brain Lang 115].

  11. Practice and Colour-Word Integration in Stroop Interference

    Science.gov (United States)

    Gul, Amara; Humphreys, Glyn W.

    2015-01-01

    Congruency effects were examined using a manual response version of the Stroop task in which the relationship between the colour word and its hue on incongruent trials was either kept constant or varied randomly across different pairings within the stimulus set. Congruency effects were increased in the condition where the incongruent hue-word…

  12. A Toy Model of Colour Screening in the Proton

    CERN Document Server

    Dischler, J; Dischler, Johann; Sjöstrand, Torbjörn

    2001-01-01

    In hadronic collisions, the mini-jet cross section is formally divergent in the limit pT -> 0. We argue that this divergence is tamed by some effective colour correlation length scale of the hadron. A toy model of the hadronic structure is introduced, that allows an estimate of the screening effects, and especially their energy dependence.

  13. Higher-Order Coloured Unification and Natural Language Semantics

    CERN Document Server

    Gardent, C; Gardent, Claire; Kohlhase, Michael

    1996-01-01

    In this paper, we show that Higher-Order Coloured Unification - a form of unification developed for automated theorem proving - provides a general theory for modeling the interface between the interpretation process and other sources of linguistic, non semantic information. In particular, it provides the general theory for the Primary Occurrence Restriction which (Dalrymple, Shieber and Pereira, 1991)'s analysis called for.

  14. Correlation Analysis of Groundwater Colouration from Mountainous Areas, Ghana

    Directory of Open Access Journals (Sweden)

    R. Amfo-Otu

    2014-03-01

    Full Text Available Access to potable water is important for human development but inhabitants of mountainous areas face challenges of water supply due to inadequacy of the available surface water. Groundwater thus becomes the other alternative. The research was done on the groundwater quality with respect to colouration in five boreholes in some second cycle schools located in mountainous areas of the Akuapim North district. Four samples each were taken from the five boreholes for laboratory analysis. Colour, iron, manganese and some physical parameters were analysed and the results were compared with the World Health Organisation guidelines and the Ghana Urban Water Limited standard for drinking water. The results showed that conductivity and turbidity were all within the acceptable standards for drinking water. Colour strongly correlated positively with iron (r = 0.869, turbidity (r = 0.858, conductivity (r = 0.727 and manganese (r = 0.681, but pH (r = -0.715 strongly correlated negatively. Even though iron and manganese have no known health effects, they were associated with the colouration of the groundwater causing aesthetic problems for the users of the boreholes. Construction of a simple filter bed with aeration facility is critical to remove iron and manganese from the water to make it potable to the consumers. DOI: http://dx.doi.org/10.5755/j01.erem.67.1.4545

  15. Normative data for Raven's Coloured Progressive Matrices scale in Yemen.

    Science.gov (United States)

    Khaleefa, Omar; Lynn, Richard

    2008-08-01

    Results are reported for a standardization sample of 986 6- to 1-yr.-olds for the Coloured Progressive Matrices in Yemen. Younger children performed better than older children relative to British norms, and there was no significant sex difference in means or variability. In relation to a British IQ of 100 (SD=15), the sample obtained an average IQ of approximately 81.

  16. A Kenya Standardization of the Raven's Coloured Progressive Matrices.

    Science.gov (United States)

    Costenbader, Virginia; Ngari, Stephen Mbugua

    2001-01-01

    Establishes a Kenyan standardization of the Raven's Coloured Progressive Matrices (RCPM), a nonverbal instrument widely used to assess academic aptitude in young children. Data was gathered from a sample of 1,370 children between the ages of 6 and 10 years. Using the current data, the RCPM appears to be a reliable and valid instrument for use in…

  17. Colour and carotenoid changes of pasteurised orange juice during storage.

    Science.gov (United States)

    Wibowo, Scheling; Vervoort, Liesbeth; Tomic, Jovana; Santiago, Jihan Santanina; Lemmens, Lien; Panozzo, Agnese; Grauwet, Tara; Hendrickx, Marc; Van Loey, Ann

    2015-03-15

    The correlation of carotenoid changes with colour degradation of pasteurised single strength orange juice was investigated at 20, 28, 35 and 42°C for a total of 32 weeks of storage. Changes in colour were assessed using the CIELAB system and were kinetically described by a zero-order model. L(∗), a(∗), b(∗), ΔE(∗), Cab(∗) and hab were significantly changed during storage (pcolour parameters were 64-73 kJ mol(-1). Several carotenoids showed important changes and appeared to have different susceptibilities to storage. A decrease of β-cryptoxanthin was observed at higher temperatures, whereas antheraxanthin started to decrease at lower temperatures. Depending on the time and temperature, changes in carotenoids could be due to isomerisation reactions, which may lead to a perceptible colour change. Although the contribution of carotenoids was recognised to some extent, other reactions seem of major importance for colour degradation of orange juice during storage.

  18. Ultraviolet sensitivity and colour vision in raptor foraging.

    Science.gov (United States)

    Lind, Olle; Mitkus, Mindaugas; Olsson, Peter; Kelber, Almut

    2013-05-15

    Raptors have excellent vision, yet it is unclear how they use colour information. It has been suggested that raptors use ultraviolet (UV) reflections from vole urine to find good hunting grounds. In contrast, UV plumage colours in songbirds such as blue tits are assumed to be 'hidden' communication signals, inconspicuous to raptors. This ambiguity results from a lack of knowledge about raptor ocular media transmittance, which sets the limit for UV sensitivity. We measured ocular media transmittance in common buzzards (Buteo buteo), sparrowhawks (Accipiter nisus), red kites (Milvus milvus) and kestrels (Falco tinnunculus) so that, for the first time, raptor UV sensitivity can be fully described. With this information, and new measurements of vole urine reflectance, we show that (i) vole urine is unlikely to provide a reliable visual signal to hunting raptors and (ii) blue tit plumage colours are more contrasting to blue tits than to sparrowhawks because of UV reflectance. However, as the difference between blue tit and sparrowhawk vision is subtle, we suggest that behavioural data are needed to fully resolve this issue. UV cues are of little or no importance to raptors in both vole and songbird interactions and the role of colour vision in raptor foraging remains unclear.

  19. Tuning the colour of white polymer light emitting diodes

    NARCIS (Netherlands)

    Kok, M.M. de; Sarfert, W.; Paetzold, R.

    2010-01-01

    Colour tuning of white polymer light emitting diode (LED) light sources can be attained by various methods at various stages in the production process of the lamps and/or by the design of the active material incorporated in the LEDs. In this contribution we will describe the methods and discuss the

  20. Perceptibility and acceptability thresholds for colour differences in dentistry

    NARCIS (Netherlands)

    Khashayar, G.; Bain, P.A.; Salari, S.; Dozic, A.; Kleverlaan, C.J.; Feilzer, A.J.

    2014-01-01

    Introduction Data on acceptability (AT) and perceptibility thresholds (PT) for colour differences vary in dental literature. There is consensus that the determination of ΔE* is appropriate to define AT and PT, however there is no consensus regarding the values that should be used. The aim of this cl