In vitro photodynamic inactivation of Cryptococcus neoformans melanized cells with chloroaluminum phthalocyanine nanoemulsion

The selection of fungi resistant to currently used fungicides and the emergence of new pathogenic species make the development of alternative fungus-control techniques highly desirable. Photodynamic antimicrobial chemotherapy (PACT) is a promising method which combines a nontoxic photosensitizer (PS) with visible light to cause selective killing of microbial cells. The development of PACT to treat mycoses or kill fungi in the environment depends on identifying effective PS for the different pathogenic species and delivery systems able to expand and optimize their use. In the present study, the in vitro susceptibility of Cryptococcus neoformans melanized cells to the photodynamic effects of the PS agent ClAlPc in nanoemulsion (ClAlPc/NE) was examined. Cells were killed in a PS concentration- and light dose-dependent manner. Treatment with ClAlPc/NE, using PS concentrations (e.g. 4.5 μm) and light doses (e.g. 10 J cm(-2)) compatible with PACT, resulted in a reduction of up to 6 logs in survival. Washing the cells to remove unbound PS before light exposure did not inhibit fungal photodynamic inactivation. Internalization of ClAlPc by C. neoformans was confirmed by confocal fluorescence microscopy, and the degree of uptake was dependent on PS concentration.     

Both solar UVA and UVB radiation impair conidial culturability and delay germination in the entomopathogenic fungus Metarhizium anisopliae.

The entomopathogenic hyphomycete Metarhizium anisopliae has been used in programs of agricultural pest and disease vector control in several countries. Exposure to simulated solar radiation for a few hours can completely inactivate the conidia of the fungus. In the present study we determined the effect of exposures to full-spectrum sunlight and to solar ultraviolet A radiation at 320-400 nm (UVA) on the conidial culturability and germination of three M. anisopliae strains. The exposures were performed in July and August 2000 in Logan, UT. The strains showed wide variation in tolerance when exposed to full-spectrum sunlight as well as to UVA sunlight. Four-hour exposures to full-spectrum sunlight reduced the relative culturability by approximately 30% for strain ARSEF 324 and by 100% for strains ARSEF 23 and 2575. The relative UV sensitivity of the two more sensitive strains was different under solar UV from that under ultraviolet B radiation at 280-320 nm (UVB) in the laboratory. Four-hour exposures to solar UVA reduced the relative culturability by 10% for strain ARSEF 324, 40% for strain ARSEF 23 and 60% for strain ARSEF 2575. Exposures to both full-spectrum sunlight and UVA sunlight delayed the germination of the surviving conidia of all three strains. These results, in addition to confirming the deleterious effects of UVB, clearly demonstrate the negative effects of UVA sunlight on the survival and germination of M. anisopliae conidia under natural conditions. The negative effects of UVA in sunlight also emphasize that the biological spectral weighting functions for this fungus must not neglect the UVA wavelengths.     

SOLAR UVB-ALBEDO OF VARIOUS SURFACES

Abstract— Measurements of the albedo of various surfaces in open grounds show significant differences for solar UVB radiation and total solar radiation (0.3–3μm). Above grassland, that albedo for solar UVB radiation is significantly smaller than that for total solar radiation (UVB: 1.3%, total: 20.7%); contrary to that, the albedo for UVB radiation is significantly higher above new dry snow (UVB: 94.4%, total: 87.0%). Consequences resulting therefrom are being quantitatively discussed with respect to the solar radiant exposure of individuals standing outdoors. Keratitis Solaris, for example, hardly occurs in snow-free terrain, even at high solar irradiance in summer; it occurs, however, in snow-covered terrain, in spite of low solar irradiance in winter and spring.     

Effects of Light Environment During Culture on UV-lnduced Cyclobutyl Pyrimidine Dimers and Their Photorepair in Rice (Oryza sativa L.)

Abstract— We examined the effects of a light environment during culture of rice plants ( Oryza sativa ) on the steady-state cyclobutyl pyrimidine dimer (CPD) level, CPD induction by challenge UVB exposure and the ability to photorepair CPD. The steady-state CPD level in plants grown under visible radiation with supplemental UVB radiation in a growth chamber was several times higher than in plants grown without supplemental UVB radiation, whereas in outdoor-grown plants, it was not enhanced by supplemental UVB radiation. The susceptibility to CPD induction by challenge UVB exposure was highest in dark-grown plants and decreased with increasing irradiance of visible radiation at low and high levels and outdoors. Chronic UVB radiation reduced the susceptibility to UV-induced CPD in plants grown both indoors and outdoors. There was a significant negative correlation between CPD levels induced by challenge UVB exposure and the content of UV-absorbing compounds. The UV-induced CPD could be reduced by subsequent blue radiation in all samples except in dark-grown seedlings. The higher the irradiance of visible radiation in the culture, the greater the ability to photorepair CPD. Chronic UVB radiation did not increase the ability to photorepair CPD.     

The Effect of Chronic Exposure to Artificial UVB Radiation on the Survival and Reproduction of Daphnia magna Across Two Generations

We examined the effects of daily (chronic) exposure to artificial UVB radiation on the survival and reproduction of Daphnia   magna over two generations. Control and experimental animals in each generation (parental and F1) were exposed to 16 h of UVA radiation and photosynthetically active radiation daily. In addition, experimental animals were exposed to 6 h of UVB during the middle of the light period. Survival and reproduction were followed for 12 days for each individual. Survival and production of F1 were significantly lower in the UVB exposed parental generation Daphnia than in controls. F1 exposure to UVB significantly decreased F1 survival and reproduction. Reproduction was lowest in UVB exposed F1 animals whose parents were also exposed to UVB. Adverse effects of UVB on offspring production may be magnified in successive generations suggesting that short-term experiments could underestimate the impact of increased UVB exposure on populations.     

TNO Institute of Environmental Sciences, Energy Research and Process Innovation, the Netherlands

Abstract— A radiative transfer model is used to study the effect of stratospheric ozone depletion and tropospheric pollution on UVB (280-315 nm) radiation in the troposphere at midiatitudes of the Northern Hemisphere. The difference in the vertical distribution of UVB radiation for a range of pollution conditions typical for remote clean and more polluted sites on cloudless summer days is shown. The changes in downward UVB irradiance, UVB actinic flux, DNA-weighted UV radiation and photodissociation frequency of ozone at the earth's surface are quantified in relation to stratospheric ozone depletion and typical ranges of tropospheric pollutants (ozone [O3], sulfur dioxide [SO₂] and aerosols) in nonurban polluted regions. The results show that near the earth's surface, in non-urban polluted regions, an increase of tropospheric pollution, which occurred over the last 50-100 years, has cancelled the effect of an increase of UVB radiation due to stratospheric ozone depletion that has occurred since the late 1970s. The results hold for summer conditions and the decrease of UVB radiation is most pronounced in the polluted boundary layer. At higher altitudes the effect of tropospheric pollution on UVB radiation is far less. Prior to 1970 it was mainly tropospheric pollution that altered UVB radiation at the surface of the earth. In addition, since the late 1970s enhanced UVB radiation reaching the top of the troposphere, due to stratospheric ozone depletion, also had an impact on UVB levels in the troposphere.     

Antifungal activity of plumericin and isoplumericin

This study evaluated the in vitro antifungal activity of the chloroform extract of Plumeria bicolor and its phytoconstituents plumericin and isoplumericin against Candida species and Cryptococcus neoformans by measuring the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC). Plumericin's consistently high activity against Candida albicans, C. krusei, C. glabrata, C. tropicalis and Cryptococcus neoformans was more potent than isoplumericin and the standard antifungal drug nystatin suggesting its potential as a drug candidate for candidiasis and cryptococcosis.     

Tetranorditerpene lactones, potent antifungal antibiotics for human pathogenic yeasts, from a unique species of Oidiodendron

The culture filtrate of a fungus isolated from decaying Picea glauca wood and tentatively identified as Oidiodendron cf. truncatum showed strong antibiotic activity against the pathogenic yeast, Candida albicans. Four new tetranorditerpenoids, oidiodendrolides A (3), B (4), and C (5) and oidiodendronic acid (7) were isolated along with three known tetranorditerpenoids, LL-Z1271 alpha (= PR1387) (1), PR1388 (2), and acrostalidic acid (6), from rice fermented by the above fungus. The structures of oidiodendrolides A (3), B (4), and C (5) and oidiodendronic acid (7) were established on the basis of spectroscopic and chemical investigations. The antifungal activity of the above tetranorditerpenoids against the pathogenic yeasts, Candida albicans and Cryptococcus neoformans is discussed.     

UVB-INDUCED SUPPRESSION OF THE MIXED EPIDERMAL CELL LYMPHOCYTE REACTION IS CRITICALLY DEPENDENT ON IRRADIANCE

The mixed epidermal cell lymphocyte reaction (MECLR) is a commonly used method to study the effects of ultraviolet B (UVB) radiation on the skin immune system. In UVB experiments dosimetry is very important. The influence of irradiance on the MECLR was studied in vitro using Philips FS40 lamps with variable UV intensities. Irradiation of isolated epidermal cells with high irradiance impaired the alloactivating capacity more than irradiation with low irradiance. In vivo, the influence of long-term UVB exposure on the MECLR was studied by treating normal healthy volunteers with suberythemagenic doses of UVB thrice weekly during 4 weeks. The first set of experiments, using low irradiance Sylvania UV-21 F75/85 W lamps, resulted in a decrease of MECLR responses of 83.1%. In the second set of experiments performed a year later, employing an identical protocol except for the use of high irradiance Waldmann UV-21 F85/100 W lamps, an increase of MECLR responses of 99.7% was observed. Volunteers of both sets of experiments received equal doses of UVB. In conclusion, this study shows that in vitro UVB-induced suppression of the MECLR is critically dependent on irradiance and therefore might explain contradictory results described in the literature. The in vivo data suggest that, comparable to the in vitro experiments, irradiance may influence the effects of UVB irradiation in vivo. Further experiments should prove whether this is indeed the case.     

Effect of Cloud Cover on UVB Exposure Under Tree Canopies: Will Climate Change Affect UVB Exposure?

The effect of cloud cover on the amount of solar UV radiation that reaches pedestrians under tree cover was evaluated with a three-dimensional canopy radiation transport model. The spatial distribution of UVB irradiance at the base of a regular array of spherical tree crowns was modeled under the full range of sky conditions. The spatial mean relative irradiance (I), and erythemal irradiance of the entire below-canopy domain and the spatial mean relative irradiance and erythemal irradiance in the shaded regions of the domain were determined for solar zenith angles from 15° to 60°. The erythemal UV irradiance under skies with 50% or less cloud cover was not remarkably different from that under clear skies. In the shade, the actual irradiance was greater under partly cloudy than under clear skies. The mean ultraviolet protection factor for tree canopies under skies with 50% or less cloud cover was nearly equivalent to that for clear sky days. Regression equations of spatially averaged I_r . as a function of cloud cover fraction, solar zenith angle and canopy cover were used to predict the variation in erythemal irradiance in different land uses across Baltimore, MD.     

Hyperbranched rolling circle amplification as a rapid and sensitive method for species identification within the Cryptococcus species complex

The Cryptococcus species complex contains two closely related basidiomycetous yeasts: Cryptococcus neoformans and C. gattii, which cause cryptococcosis in humans and other animals. The species and varieties are characterized, by different clinical, epidemiological, biochemical and molecular features. The currently used identification methods are either time-consuming or not anymore commercially available. However, a rapid, sensitive and robust assay for the detection of these pathogens is vital for early diagnosis and appropriate treatment decisions. To overcome those limitations, four padlock probes targeting species-specific single nucleotide polymorphisms at the internal transcribed spacers (ITSs) of the RNA gene locus were developed and applied during isothermal hyperbranched rolling circle amplification (HRCA). The probes were tested against 99 samples, including 94 clinical cryptococcal cultures, three closely related Cryptococcus species, and two clinical specimens. The use of the padlock probes and the combination of probe signal amplification by HRCA provided a quick and sensitive assay for the accurate identification of C. neoformans var. grubii, C. neoformans var. neoformans and C. gattii. HRCA was also useful to detect hybrids, when they were heterozygous at the ITS locus. The HRCA results were in agreement with previous genotyping data based on PCR fingerprinting, amplified fragment length polymorphism and ITS sequencing.     

Decrease in langerhans cells and increase in lymph node dendritic cells following chronic exposure of mice to suberythemal doses of solar simulated radiation

Exposure of certain strains of mice to ultraviolet radiation (UVR) causes suppression of some innate and adaptive immune responses. One such consequence of acute UVB exposure is a reduction in the number of Langerhans cells (LC) in the epidermis and an increase in dendritic cells (DC) in lymph nodes draining the irradiated skin sites. Exposure to chronic UVB irradiation also has effects on the immune system, but it is unknown what effects are caused by repeated doses of solar simulated radiation (SSR). Consequently, the main aims of the present study were to determine whether repeated exposure to low doses of SSR would lead to similar changes in these cell populations and whether chronic doses of SSR activate a protective photoadaptation mechanism. Groups of C3H/HeN mice were irradiated daily with 3.7 J/cm(2) SSR from Cleo Natural lamps for 2, 10, 20, 30 or 60 days. Further groups of mice received an additional dose of 7.4 J/cm(2) SSR on days 2, 10, 30 or 60 to test for photoadaptation. The numbers of LC in the epidermis and DC in the lymph nodes draining irradiated skin sites were counted 24 h after the final irradiation. With the exception of mice irradiated for only 2 days, LC were significantly reduced throughout the chronic irradiation protocol, and no recovery occurred. DC numbers were significantly increased in the draining lymph nodes of mice irradiated for 20 days and 60 days.     

NON-NUCLEAR DAMAGE AND CELL LYSIS ARE INDUCED BY UVA, BUT NOT UVB OR UVC, RADIATION IN THREE STRAINS OF L5178Y CELLS

The potential to induce non-nuclear changes in mammalian cells has been examined for (1) UVA1 radiation (340–400 nm, UVASUN 2000 lamp), (2) UVA + UVB (peak at 313 nm) radiation (FS20 lamp), and (3) UVC (254 nm) radiation (GI5T8 lamp). The effects of irradiation were monitored in vitro using three strains of L5178Y (LY) mouse lymphoma cells that markedly differ in sensitivity to UV radiation. Comparisons were made for the effects of approximately equitoxic fluences that reduced cell survival to 1–15%. Depending on the cell strain, the fluences ranged from 830 to 1600 kJ/m² for the UVASUN lamp, 75 to 390 J/m² for the FS20 lamp and 3.8 to 17.2 J/m² for the G15T8 lamp. At the exposure level used in this study, irradiation with the UVASUN, but not the FS20 or G15T8, lamp induced a variety of non-nuclear changes including damage to cytoplasmic organelles and increased plasma membrane permeability and cell lysis. Cell lysis and membrane permeabilization were induced by the UVA1 emission of the UVASUN lamp, but not by its visible + IR components (>400 nm). The results show that the plasma membrane and other organelles of LY cells are highly sensitive to UVA1 but not to UVB or UVC radiation. Also UVA1, but not UVB or UVC radiation, causes rapid and extensive lysis of LY cells. In conclusion, non-nuclear damage contributes substantially to UVA cytotoxicity in all three strains of LY cells.     

Effects of Ultraviolet-B Exposure on the Resistance to Listeria monocytogenes in the Rat

A rat infection model using the bacterial pathogen Listeria monocytogenes was employed to analyze the im-munosuppressive activity of UVB radiation. Rats were exposed to suberythemal doses of UVB radiation for 5 or 7 consecutive days, using Kromayer or FS40 lamps respectively. Subsequently, the rats were infected subcuta-neously or intravenously with Listeria . Exposure to UVB resulted in an increased number of bacteria in the spleen 4 days after infection. Listeria -specific lymphocyte proliferation assays as well as delayed-type hypersensitivity reactions demonstrated that T cell-mediated immunity to Listeria was impaired by UVB as measured 4 and 8 days after infection. In addition, UVB exposure decreased phagocytotic activity of peripheral blood macrophages. This study demonstrated that suberythemal doses of UVB radiation caused a delay in the clearance of Listeria bacteria from the spleen of the rats and that this was probably caused by impaired nonspecific phagocytosis of Listeria by macrophages in addition to an impaired activity of Listeria -specific T cells.     

Evidence Regarding the Possible Role of c-Phycoerythrin in Ultraviolet-B Tolerance in a Thermophilic Cyanobacterium*

Abstract— It was recently reported that a strain of Nostoc spongiaeforme (cyanobacteria) with the photopigment c-phycoerythrin (c-PE) may be more tolerant of the adverse effects of UVB radiation than the same strain lacking c-PE due to chromatic adaptation (CA) (Tyagi et al., Photochem. Photobiol. 55,401–407, 1992). It was proposed that this increased UVB tolerance may be due to the presence of c-PE, perhaps as a function of the ability of strains with c-PE to chromatically adapt. We tested the role of c-PE in UVB tolerance by comparing the short-and long-term effects of UVB exposure on photosynthesis, pigmentation and the protein contents of four experimental cultures of the thermophilic cyanobacterium Os-cillatoria cf. amphigranulata. These cultures consisted of a wild-type strain that produces c-PE, a green pigment variant (subcloned from the parent wild-type strain) incapable of producing c-PE and two chromatically adapted color forms of the wild-type strain that varied with regard to their total c-PE content. There were no significant results suggesting a role for c-PE in UVB tolerance. It is concluded that the photopigment c-PE does not confer enhanced resistance to the deleterious effects of UVB radiation on photosynthesis in this cyanobacterium.     

POTENTIAL ERRORS IN THE USE OF CELLULOSE DIACETATE AND MYLAR FILTERS IN UV-B RADIATION STUDIES

Abstract— The increase in UV-B radiation(290–320 nm) penetrating to the earth's surface as a result of the chemical depletion of the stratospheric ozone layer is an important environmental concern. In most studies using artificial UV-B sources, the determination of enhanced UV-B radiation effects on plants relies on equivalent UV-A radiation(320–400 nm) from the experimental UV-B fluorescent lamp source, filtered with either cellulose diacetate (CA) to create UV-B treatments, or with type S Mylar or polyester (PE) to create controls (no UV-B). The spectral irradiance in the UV-A was measured in the dark below lamps at two daily UV-B irradiance levels (14.1 and 10.7 W m^-2) with CA and PE at two ages. Highly significant differences in UV-A radiation (P 0.01) were measured below the treatment/control pairs at both fluence rates and filter ages. Filter aging was observed, which reduced the UV-A irradiance, especially for PE. The total daily ambient UV-A irradiance was also determined in the glasshouse at three seasons: the fall equinox, summer and winter, from which the total daily UV-A (lamp + ambient) irradiances were calculated. The addition of low to moderate ambient irradiance removed the treatment/control differences in the longwave UV-A(350–400 nm); however, the treatment/contro1 differences remained in the shortwave UV-A(320–350 nm), which was restricted by the glass, and in the total UV-A. The treatment/control differences persisted in the shortwave UV-A for the higher irradiance level, even under high summer ambient light. Also, spectral ratios (UVB:UV-A and shortwave: longwave UV-A) for all treatment groups decreased as the ambient UV-A radiation increased. Therefore, a range of experimental conditions exist where PE-covered lamps do not provide adequate control for UV-A irradiance, relative to the CA treatment, for glasshouse/growth chamber experiments. Potential complications in the interpretation of plant response exist for UV-B experiments conducted under low ambient light conditions (e.g. growth chambers; glasshouse in winter) or high daily UV-B irradiances (e.g. 14 kJ m^-2) for those plant responses that are sensitive to UV-A radiation.     

Spectral UV irradiance on vertical surfaces: a case study

The UV spectral irradiance on horizontal and vertically oriented surfaces was measured throughout a cloudless day (18 July 1995) at Izana station, Tenerife, using a Bentham DTM300 spectroradiometer scanning from 290 to 500 nm in steps of 5 nm. Results show that irradiance measured on a horizontal surface is not proportional to irradiance on a vertical surface. The relation between the two depends upon orientation of the vertical surface, zenith angle and wavelength. At short UVB wavelengths surfaces directed toward the solar azimuth received their maximum irradiances much closer to solar noon than the maxima for longer wavelengths. Some vertical surfaces also received significantly more irradiance than the horizontal surface at long wavelengths during all but the central hours of the day, while at short wavelengths all vertical irradiances were less than the horizontal except for the measurements at the extreme ends of the day. Erythemally effective radiation followed the diurnal pattern of irradiations for short UVB wavelengths.     

Effects of Ultraviolet Radiation (UVA+UVB) and Copper on the Morphology,Ultrastructural Organization and Physiological Responses of the Red Alga Pterocladiella capillacea

The effect of ultraviolet (UV) radiation and copper (Cu) on apical segments of Pterocladiella capillacea was examined under two different conditions of radiation, PAR (control) and PAR+UVA+UVB (PAR+UVAB), and three copper concentrations, ranging from 0 (control) to 0.62, 1.25 and 2.50 μm . Algae were exposed in vitro to photosynthetically active radiation (PAR) at 70 μmol photons m^?2 s^?1, PAR + UVB at 0.35 W m^?2 and PAR +UVA at 0.70 W m^?2 during a 12‐h photocycle for 3 h each day for 7 days. The effects of radiation and copper on growth rates, content of photosynthetic pigments and photosynthetic performance were analyzed. In addition, samples were processed for light and transmission electron microscopy. The content of photosynthetic pigments decreased after exposure to radiation and Cu. Compared with PAR radiation and copper treatments modified the kinetics patterns of the photosynthesis/irradiance curve. The treatments also caused changes in the ultrastructure of cortical and subcortical cells, including increased cell wall thickness and accumulation of plastoglobuli, as well as changes in the organization of chloroplasts. The results indicate that the synergistic interaction between UV radiation and Cu in P. capillacea, led to the failure of protective mechanisms and causing more drastic changes and cellular imbalances.     

Daphnia pulex Fed UVB-lrradiated Chlamydomonas reinhardtii Show Decreased Survival and Fecundity†

Abstract The ability to avoid or tolerate UVB radiation (290–320 nm) probably reduces the quality of phytoplankton as food for zooplankton. Ultraviolet avoidance forces motile algae lower in the water column, reducing net primary productivity. Production of UV-absorbing compounds as a tolerance mechanism takes carbon and energy away from cell growth; these compounds are also less useful as food for herbivores. We assessed the food quality of UVB-irradiated Chlamydomonas reinhardtii Dang, by analysis of cohort life tables for the herbivore Daphnia pulex Leydig. Algal cultures were grown under fluorescent lights interspersed with UV bulbs (20°C, 16 h light: 8 h dark) and covered with either cellulose acetate (+UVB) or Mylar D (-UVB). After a 7 day UVB exposure, carotenoid levels of C. reinhardtii were significantly greater than in unexposed cultures; there were no significant differences in chlorophyll, lipid, protein or nonstructural carbohydrate levels. After an initial decrease in growth rate, UVB-exposed algae recovered and final growth rates of both cultures were similar after 7 days. Daphnia neonates were raised under optimal conditions (20°C, 16 h light:8 h dark) and fed either UVB-irradiated or control algae. Daphnia fed UVB-irradiated algae had significantly increased mortality, decreased growth rate at the time of first clutch production, delayed release of the first clutch and decreased overall fecundity (P < 0.05). Daphnia were also less efficient at clearing UVB-irradiated algae from the water column (17% removal in 18 h) when compared with Daphnia that grazed upon nonirradiated algae (85% removal in 18 h). These data suggest that even though UVB-irradiated algal populations can recover from their initial decline, their predators may not be able to utilize them as an effective food source. Therefore, the impacts of UVB radiation within     

Multi-waveband solar irradiance on tree-shaded vertical and horizontal surfaces: cloud-free and partly cloudy skies

Irradiance measurements of short wave (SW), photosynthetically active (PAR), ultraviolet-A (UVA) and ultraviolet-B (UVB) solar radiations were made on horizontal and vertical surfaces in the shade of trees under cloud-free and partly cloudy skies. All measurements were referenced to the irradiance of a horizontal surface above the canopy. For horizontal shaded surfaces under cloud-free skies, the values of the ratio (Rh) of below- to above-canopy horizontal irradiance were similar for the UVA and UVB wavebands and for the SW and PAR wavebands. However, Rh for the UV wavebands differed from that for the PAR and SW wavebands. Overall, values of Rh in the shade typically varied as PAR < SW < UVA < UVB. The irradiance ratios for vertical surface in the shade typically varied as UVB > UVA = SW > PAR. In absolute terms, UVB irradiance (Ih) on tree-shaded horizontal surfaces increased relative to a cloud-free sky when a translucent cirroform cloud was in front of the sun, but decreased when the cloud was in a region of sky away from the sun. Translucent cirroform cloud cover also tended to decrease the UVB irradiance (Iv) for a shaded vertical surface (either facing the sun or south) relative to that under cloud-free skies, regardless of where the clouds were in the sky. In all other wavebands the shaded Ih and Iv increased under translucent cirroform cloud cover relative to cloud-free skies, regardless of where the clouds were in the sky.