Mesopic radial frequency contrast sensitivity function for young and older adults

The objective of the present study was to determine contrast sensitivity curves of concentric circular patterns with radial frequencies of 0.25, 0.5, 1.0, 2.0, and 4.0 cycles per degree in young and older adult volunteers. These parameters were also compared with sensitivity contrasts for sine-wave gratings. All participants had normal acuity vision and were free of identifiable ocular illness. Contrast sensitivity was measured in 6 young adults aged 19 to 23 years and 6 older adults aged 60 to 69 years using the psychophysical forced-choice method. In this paradigm the volunteers had to decide which of two stimuli contained the above radial frequencies at low contrast levels. The other neutral stimulus was gray with homogeneous luminance. We detected a decline in contrast sensitivity for older adults at all radial frequencies compared to young adults. Also, contrast sensitivity for sine-wave gratings at all measured frequencies was better, as predicted, for all young adults. Maximum sensitivities in the radial frequency contrast sensitivity function and contrast sensitivity function occurred at 0.25 and 0.5 cycles per degree, respectively, for both young and older adults. These results suggest age-related changes in the contrast sensitivity function for concentric symmetrical stimuli.

Causação circular do crescimento das economias em desenvolvimento: uma ponte entre as abordagens evolucionária e pós keynesiana

Based on the Post Keynesian approach and on the Evolutionary literature, this study seeks to demonstrate the causal relationships between the National Innovation System and the national and international financial systems. This study shows that there is a circular causation in the less developed economies that contributes to the immaturity of its National Innovation System and to its structural external vulnerability. Conclusions highlight that the cycles in the less developed economies mirror the cycles of international liquidity.

William Hamilton Merritt Welland Canal circular, July 12, 1823

William Hamilton Merritt (1793-1862) was a soldier, merchant, and politician who was instrumental in the promotion and development of the Welland Canal. After serving with the Lincoln militia during the War of 1812, Merritt became a merchant in St. Catharines, and purchased some land on Twelve Mile Creek on which he ran a sawmill and constructed a grist mill. He initially envisioned a canal between the Welland River and Twelve Mile Creek, which evolved into a plan to link Lake Ontario and Lake Erie. This would enable goods from western Canada to be conveniently shipped to Montreal and Great Britain through the St. Lawrence, while bypassing the Niagara portage. His plan met with opposition for financial and political reasons, as well as from those along the Niagara portage whose businesses would suffer if the canal were built. Despite this opposition, the Welland Canal Company was chartered by the Upper Canadian assembly in January, 1824. Construction on the canal began later that year, and was completed in 1829.

William Hamilton Merritt Welland Canal circular, July 12, 1823

William Hamilton Merritt (1793-1862) was a soldier, merchant, and politician who was instrumental in the promotion and development of the Welland Canal. After serving with the Lincoln militia during the War of 1812, Merritt became a merchant in St. Catharines, and purchased some land on Twelve Mile Creek on which he ran a sawmill and constructed a grist mill. He initially envisioned a canal between the Welland River and Twelve Mile Creek, which evolved into a plan to link Lake Ontario and Lake Erie. This would enable goods from western Canada to be conveniently shipped to Montreal and Great Britain through the St. Lawrence, while bypassing the Niagara portage. His plan met with opposition for financial and political reasons, as well as from those along the Niagara portage whose businesses would suffer if the canal were built. Despite this opposition, the Welland Canal Company was chartered by the Upper Canadian assembly in January, 1824. Construction on the canal began later that year, and was completed in 1829

El cura del Sagrario de Querétaro, refuta un folleto, que con el título: Lo que creen los protestantes ha hecho circular en esta ciudad, Mr. Almon W. Greeman, ministro protestante de la iglesia llamada Evangélica

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Relación que en apoyo de la representación en contra de la circular de 17 de enero próximo pasado presenta al Supremo Gobierno, el ciudadano Pedro Vander-Linden.

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Comunicación circular que el Exmo. Sr. Don Manuel de la Peña y Peña, estendió en el año de 1845, como ministro de relaciones, para dirigirla a los gobiernos y asambleas de partamentales, sobre la cuestión de paz o guerra, según el estado que guardaban en aquella época

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Circular expedida por el C. Licenciado Protasio P. Tagle, Ministro de Gobernación, en que se dan a conocer las negociaciones entabladas con el C. Lic. José María Iglesias, para dar término a la guerra civil, y que fueron rotas por su parte

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Circular del Ilmo. Sr. Doctor Don Cresencio Carrillo y Ancona Obispotitular de Lero y Coadjutor de Yucatán sobre la coronación de Ntra.Sra. de Guadalupe y sobre el jubileo sacerdotal de su Santidad el Señor León XIII y de su Señoría Ilustrisíma Dignísi

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Circular sobre la sagrada predicación

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Circular Diocesana, expedida por el Ilmo. Sr. Obispo de Cuernavaca,con motivo de la función que esta Sagrada Mitra celebrará en la Colegiata de Guadalupe...

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Circular dirigida por el Ilmo. Sr. Arzobispo de México al Ilmo. y Ve. Cabildo Metropolitano, al de la insigne Colegiata de Guadalupe, al clero secular y regular y a todos sus diocesanos

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