This study analyzed the fluctuation of the achromatic visual contrast sensitivity (CS) of adult males (M = 23.42 ± 2.6 years) during a daily period. Twenty-eight volunteers were divided into three groups according to circadian typology (CT): moderate morning (MM; n = 8); intermediate (I; n = 10) and moderate evening (ME; n = 10). The Pittsburgh Sleep Quality Index was used to evaluate sleep quality, and the Horne and Ostberg Morningness-Eveningness Questionnaire was used to measure CT. To measure CS, we used Metropsis software version 11.0 with vertical sinusoidal grids of 0.2, 0.6, 1, 3.1, 6.1, 8.8, 13.2 and 15.6 cycles per degree of visual angle (cpd). The stimuli were presented on a cathode ray tube (CRT) color video monitor with a 19-inch flat screen, a 1024 × 786 pixel resolution, a 100 Hz refresh rate and a photopic luminance of 39.6 cd/m. It was inferred that there is a tendency for visual contrast to vary according to daily rhythmicity and CT, mainly for the median spatial frequencies (1.0 cpd, χ = 9.93, p < 0.05 and 3.1 cpd, χ = 10.33, p < 0.05) and high spatial frequencies (13.2 cpd, χ = 11.54, p < 0.05) of ME participants. ME participants had minimal visual contrast sensitivity during the morning shift and a progressive increase from afternoon to night.

This study aimed to measure the axes of colors confusion according to the circadian typology (CT). For this purpose, 28 young male adults aged 20 to 28 participated in this study. The characteristics of the sample were: morning moderately (MM; n = 8; M = 23.25 ± 2.6); Intermediate (I; n = 10; M = 23.30 ± 2.7) and evening moderately (EM; n = 10; M = 23.70 ± 2.5). We used the Pittsburgh Sleep Quality Index (PSQI) and Horne and Ostberg’s questionnaire to ascertain aspects of sleep quality and CT and Cambridge Colour Test (CCT) and the Lanthony Desaturated D-15 Test (D-15d) to verify the color perception. Significant difference was found in the PSQI (F(2.20) = 15.77, p < .001; η2 = 0.62) between EM compared with I (p < .001) and MM (p < .001). We found a difference in the protan confusion axes at 9 a.m. (χ2 = 6.74; p < .05) and 9 p.m. (χ2 = 7.11; p < .05) and deutan at 5 p.m. (χ2 = 11.23, p < .001). The chromatic confusion axes will vary according to the synchronization of daily variation and the EM typology has higher chromatic sensitivity, pointing to a possible relation between visual circadian filters and spatial chromatic information. The daily fluctuation of visual sensitivity may explain the preliminary results on the circadian effects on color perception.

The goal of this study was to compare the visual contrast sensitivity (CS) of men and women exposed and not exposed to organic solvents. Forty-six volunteers of both genders aged between 18 and 41 years (mean±SD=27.72±6.28) participated. Gas station attendants were exposed to gas containing 46.30 ppm of solvents at a temperature of 304±274.39 K, humidity of 62.25±7.59% and ventilation of 0.69±0.46 m/s (a passive gas chromatography-based sampling method was used considering the microclimate variables). Visual CS was measured via the psychophysical method of two-alternative forced choice using vertical sinusoidal gratings with spatial frequencies of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0, and 16.0 cpd (cycles per degree) and an average luminance of 34.4 cd/m2. The results showed that visual CS was significantly lower (P<0.05) in the following groups: i) exposed men compared to unexposed men at frequencies of 0.2, 0.5, 1.0, and 2.0 cpd; ii) exposed women compared to unexposed women at a frequency of 5.0 cpd; and iii) exposed women compared to exposed men at a frequency of 0.5 cpd, even at exposures below the tolerance limit (300 ppm). These results suggest that the visual CS of exposed men was impaired over a wider range of spatial frequencies than that of exposed women. This difference may have been due to the higher body fat content of women compared to that of men, suggesting that body fat in women can serve as a protective factor against neurotoxic effects.

This study evaluated the level of exposure to organic vapors in chromatic and achromatic vision of 38 male gas-station workers (average of 6.82 ± 5.62 years worked). The level of exposure was found by passive method with gas chromatography. Color vision was assessed by Lanthony desaturated D15 tests (D15d; Lanthony, 1978) the Cambridge Color Test (CCT; Mollon, & Reffin, 1989), and contrast sensitivity by sinusoidal gratings at frequencies 0.2, 0.5, 1, 2.0, 5, 10 and 16 cycles per degree (cpd). The highest average daily concentrations found in gasoline (168 ppm) were below the threshold limit values (300 ppm), yet gas-station workers had a higher color-confusion index (CCI) for D15d (p < .01), predominantly for blue/yellow (75%), larger ellipse areas in the CCT (p < .05), and lower sensitivity contrast for 5, 10, and 16 cpd (p < .01). Prolonged service time correlated with the areas A1 (ρ = 0.46; p < .01), A2 (ρ = 0.63; p < .01), and 5 cpd (ρ = – 0.36; p < .05). Gas-station attendants with 8–20 years of service had lower performances for the areas A1 and A2 (p < .0083) than those with less exposure (1–3 years of service). The results show that chronic exposure to organic vapors can reduce the chromatic and achromatic visual perception of luminance in gas-station workers with age, even at low levels, suggesting the inadequacy of tolerance levels used for gasoline. The also highlight the need for chronic systematic long-term monitoring, and not just daily.

A ferrugem da folha (Puccinia coronata f. sp. avenae) é a doença mais destrutiva da aveia, e aplicações de fungicidas com volumes baixos de calda podem reduzir a eficácia do controle químico. O objetivo do trabalho foi avaliar a eficiência técnica e econômica de fungicidas, doses e volumes de calda no controle da ferrugem da folha da aveia. O experimento foi conduzido no ano de 2003, na área experimental da FAMV/UPF, com a cultivar de aveia UPFA-20. Os tratamentos foram compostos pelas combinações entre dois fungicidas (tebuconazole, Folicur, 0,75 L ha-1 e epoxiconazole + piraclostrobim, Opera, 0,5 L ha-1), quatro doses (40; 60; 80 e 100% da dose recomendada) e dois volumes de calda (100 e 200 L ha-1). O delineamento experimental foi o de blocos casualizados, com esquema fatorial (2x4x2) e quatro repetições. Avaliaram-se a severidade, o controle da ferrugem, a massa do hectolitro, a massa de mil grãos e o rendimento de grãos, realizando-se análise econômica. O volume de calda de 200 L ha-1 proporcionou maiores níveis de controle da doença. As aplicações dos fungicidas com volume de 200 L ha-1 e meia dose ou com 100 L ha-1 e dose cheia proporcionam níveis de controle da ferrugem equivalentes. O resultado econômico difere entre fungicidas e independe do volume de calda. Os efeitos de doses dependem do fungicida.