Differential tolerance to ultraviolet-B light and photoenzymatic repair in cladocerans from a Chilean lake

2004 ◽  
Vol 55 (2) ◽  
pp. 193 ◽  
Author(s):  
Rodrigo Ramos-Jiliberto ◽  
Patricia Dauelsberg ◽  
Luis R. Zúñiga
Keyword(s):  
Treatment Group ◽  
Visible Light ◽  
Ceriodaphnia Dubia ◽  
Ultraviolet B ◽  
Sensitive Species ◽  
Tolerant Species ◽  
Cladoceran Species ◽  
Different Doses

In the present study, the sensitivity of four coexisting cladoceran species to ultraviolet (UV)-B radiation was evaluated. First, the LD50 under conditions inhibiting the action of photoenzymatic repair was calculated by exposing cladocerans to different doses of UV-B light only. Animals in another treatment group were exposed to both UV-B and visible light, which allows for photoenzymatic repair. Photoenzymatic repair contributed significantly towards the degree of total tolerance to UV-B light in all groups of cladocerans, although the magnitude of the contribution varied among species. When no photoenzymatic repair was allowed, the most tolerant species was Moina micrura, followed by Daphnia ambigua and Ceriodaphnia dubia, with Diaphanosoma chilense being the most sensitive species. Under conditions permitting the action of photorepair, M. micrura was again the most tolerant species to UV-B light. Ceriodaphnia dubia showed an intermediate tolerance value, whereas D. chilense and D. ambigua were the least tolerant species, with no significant differences between them. Adults and juveniles of C. dubia differed in their sensitivity to UV-B light under conditions with and without photorepair.

scholarly journals An overview of the cutaneous porphyrias

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1906 ◽  
Author(s):  
Robert Dawe
Keyword(s):  
Liver Disease ◽  
Visible Light ◽  
Porphyria Cutanea Tarda ◽  
Marrow Transplant ◽  
Ultraviolet B ◽  
Erythropoietic Protoporphyria ◽  
Liver Iron ◽  
Underlying Liver Disease ◽  
Liver Iron Overload ◽  
Enzyme Defects

This is an overview of the cutaneous porphyrias. It is a narrative review based on the published literature and my personal experience; it is not based on a formal systematic search of the literature. The cutaneous porphyrias are a diverse group of conditions due to inherited or acquired enzyme defects in the porphyrin–haem biosynthetic pathway. All the cutaneous porphyrias can have (either as a consequence of the porphyria or as part of the cause of the porphyria) involvement of other organs as well as the skin. The single commonest cutaneous porphyria in most parts of the world is acquired porphyria cutanea tarda, which is usually due to chronic liver disease and liver iron overload. The next most common cutaneous porphyria, erythropoietic protoporphyria, is an inherited disorder in which the accumulation of bile-excreted protoporphyrin can cause gallstones and, rarely, liver disease. Some of the porphyrias that cause blistering (usually bullae) and fragility (clinically and histologically identical to porphyria cutanea tarda) can also be associated with acute neurovisceral porphyria attacks, particularly variegate porphyria and hereditary coproporphyria. Management of porphyria cutanea tarda mainly consists of visible-light photoprotection measures while awaiting the effects of treating the underlying liver disease (if possible) and treatments to reduce serum iron and porphyrin levels. In erythropoietic protoporphyria, the underlying cause can be resolved only with a bone marrow transplant (which is rarely justifiable in this condition), so management consists particularly of visible-light photoprotection and, in some countries, narrowband ultraviolet B phototherapy. Afamelanotide is a promising and newly available treatment for erythropoietic protoporphyria and has been approved in Europe since 2014.

The influence of aluminium on phosphate sorption by whole plants and excised roots of some pasture legumes

1973 ◽  
Vol 24 (3) ◽  
pp. 341 ◽  
Author(s):  
CS Andrew ◽  
PJVanden Berg
Keyword(s):  
Dry Matter ◽  
Phosphorus Uptake ◽  
Dry Matter Production ◽  
Unit Weight ◽  
Phosphorus Concentration ◽  
Sensitive Species ◽  
Pasture Legumes ◽  
Tolerant Species ◽  
Matter Production ◽  
Whole Plants

The effects of aluminium (0, 0.5, 1.0, and 2.0 p.p.m.) on dry matter production and subsequent short-term uptake and translocation of phosphorus in whole plants, and on the uptake of phosphorus by excised roots, of six tropical pasture legumes were ascertained. Macroptilium lathyroides, Desrnodiurn uncinaturn, Lotononis bainesii, and Stylosanthes hurnilis were tolerant species in terms of effects on dry matter production. Glycine wightii was a sensitive species and Medicago sativa a very sensitive one. In the whole plant study, plants were grown in Solution culture with a phosphorus concentration of 2 p.p.m., under the above aluminium treatments. Aluminium increased the subsequent uptake of phosphorus (tops+roots) in all species (phosphorus substrate concentration 1 x 10-5M labelled with 32P, 1 and 3 hr uptake periods). Phosphorus uptake in the tops of the four tolerant species was increased by aluminium treatment, and in the two sensitive species it uas reduced. In both the absence and presence of applied aluminium, L. bainesii was the most efficient species per unit weight of root tissue in sorbing total phosphorus, and in addition had the highest efficiency of translocation of phosphorus from roots to tops. S. humilis was also an efficient species. In the excised root study, addition of aluminium to the solution enhanced the sorption of phosphorus by all species. The enhancement was greater in a relatively strong phosphorus solution (2 x 10-4 M) than in a dilute solution (1 x 10-4). The sorption of phosphorus by excised roots of S. humilis from dilute and relatively strong phosphorus substrates was greater than that of other species, both in the absence and presence of added aluminium. L. bainesii was omitted from the excised root experiments.

scholarly journals Intradermal injection of umbilical cord mesenchymal stem cell was more effective than platelet rich plasma in increasing amount of collagen and fibroblasts in Wistar rats (Rattus norvegicus) back skin exposed to ultraviolet B rays

2021 ◽  
Vol 4 (1) ◽  
pp. 42-46
Author(s):  
Anne Carolina Kencanawati ◽  
Wimpie Pangkahila ◽  
Anak Agung Gde Putra Wiraguna
Keyword(s):  
Treatment Group ◽  
Umbilical Cord ◽  
Wistar Rats ◽  
Platelet Rich Plasma ◽  
Intradermal Injection ◽  
Ultraviolet B ◽  
Field Of View ◽  
Control Group ◽  
Skin Collagen ◽  
The Mean

Background: Ultraviolet B exposure is one of the causes of extrinsic skin aging. Ultraviolet exposure may lead to skin collagen damage. This study about mesenchymal stem cells from umbilical cord (UCMSC) compared with platelet rich plasma (PRP) with the aim was to prove that the intradermal injection of UCMSC was more effective than PRP in increasing amount of collagen and fibroblasts in Wistar rats' back skin exposed to Ultraviolet B rays. Methods: This study used post-test only control group design. Subjects were 36 Wistar rats aged 2.5 months. A control group consisting of 18 Wistar rats treated with intradermal injection of PRP and the treatment group with UCMSC. Both groups were exposed to UVB with a total radiation dose of 840 mJ/cm2. The parameter of collagen was determined by picro sirius red staining while fibroblasts by Haematoxylin-Eosin staining. Result: The mean amount of collagen in the control group was lower (57,82±6.52%) than the treatment group (65.69±4.51%) with p<0.001. The result showed there were differences in the number of collagen in both groups (p<0.05). The mean number of fibroblasts in the control group was lower (22.63±5.98 cell/field of view) than the treatment group (28.20±8.90 cell/field of view) with p=0.034. The result showed there were differences in mean of fibroblasts in both groups (p<0.05). Conclusion: It can be concluded that the intradermal injection of UCMSC was more effective in increasing the amount of collagen and fibroblasts than intradermal injection of PRP in Wistar rats' back skin exposed to UVB rays.

scholarly journals Rescue Blankets-Transmission and Reflectivity of Electromagnetic Radiation

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 375 ◽  
Author(s):  
Hannah Kranebitter ◽  
Bernd Wallner ◽  
Andreas Klinger ◽  
Markus Isser ◽  
Franz J. Wiedermann ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Visible Light ◽  
Heat Loss ◽  
Infrared Radiation ◽  
Experimental Studies ◽  
High Energy ◽  
Ultraviolet B ◽  
Electromagnetic Spectrum ◽  
Blue Band ◽  
Outdoor Sports

Rescue blankets are medical devices made of a polyethylene terephthalate sheet coated with a thin aluminum layer. Blankets are used for protection against hypothermia in prehospital emergency medicine and outdoor sports, but totally different qualities are typical for these multi-functional tools. On the one hand, rescue sheets prevent hypothermia by reducing thermo-convection and diminishing heat loss from evaporation and thermal radiation. On the other hand, the sheets promote cooling by acting as a radiant barrier, by providing shade and even by increasing heat conduction when the sheet is in direct contact with the skin. As foils are watertight and windproof, they can function as vapor barriers and even as stopgap bivouac sacks. We evaluated three experimental studies, one on heat loss by rescue blankets according to surface color, one on transparency with ultraviolet radiation, high-energy visible light and visible light, and one on infrared radiation from rescue blankets. When evaluating the effects of different bands of the electromagnetic spectrum on rescue sheets, we focused on ultraviolet radiation (200–380 nm), high-energy visible light in the violet/blue band (380–450 nm), visible light (380–760 nm) and infrared radiation (7500–13,500 nm). Rescue sheets transmit between 1% and 8% of visible light and about 1% of ultraviolet B radiation (280–315 nm), providing sufficient transparency and adequate protection from snow blindness. Reflection of visible light increases detectability in search and rescue missions performed in good visibility conditions, while reflection of infrared radiation increases detectability in poor visibility conditions and provides protection against hypothermia.

scholarly journals Spectrum of virucidal activity from ultraviolet to infrared radiation

2020 ◽  
Vol 19 (10) ◽  
pp. 1262-1270 ◽  
Author(s):  
Luke Horton ◽  
Angeli Eloise Torres ◽  
Shanthi Narla ◽  
Alexis B. Lyons ◽  
Indermeet Kohli ◽  
...  
Keyword(s):  
Visible Light ◽  
Infrared Radiation ◽  
Ultraviolet B ◽  
Virucidal Activity ◽  
Ultraviolet A

There is evidence that other wavelengths beyond the traditional germicidal 254 nm UVC – namely far UVC (222 nm), ultraviolet B, ultraviolet A, visible light, and infrared radiation – have germicidal properties; however, data on UVC is the most robust.

scholarly journals Absorption of α-tocopheryl acetate is limited in mink kits (Mustela vison) during weaning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saman Lashkari ◽  
Tove N. Clausen ◽  
Leslie Foldager ◽  
Søren K. Jensen
Keyword(s):  
Treatment Group ◽  
Mustela Vison ◽  
Tocopherol Content ◽  
Tocopheryl Acetate ◽  
High Dose ◽  
Ester Bond ◽  
Treatment Groups ◽  
Hydrolysis Of ◽  
Mink Kits ◽  
Different Doses

AbstractBioavailability of α-tocopherol varies with source, dose and duration of supplementation. The effect of source and dose of α-tocopherol on response of α-tocopherol stereoisomers in plasma and tissues of mink kits during the weaning period was studied. Twelve mink kits were euthanised in CO2 at the beginning of the experiment, and 156 mink kits (12 replicates per treatment group) were randomly assigned to thirteen treatment groups: no added α-tocopherol in the feed (0 dose) or four different doses (50, 75, 100 and 150 mg/kg of diet) of RRR-α-tocopherol (ALC), RRR-α-tocopheryl acetate (ACT) or all-rac-α-tocopheryl acetate (SYN). Six mink kits per treatment group were euthanised 3 weeks after initiation of the experiment, and the remaining six were euthanised 6 weeks after initiation of the experiment. The RRR-α-tocopherol content in plasma, liver, heart and lungs was affected by interaction between source and dose (P < 0.01 for all). The highest RRR-α-tocopherol content in plasma (13.6 µg/ml; LS-means for source across dose and week), liver (13.6 µg/mg), heart (7.6 µg/mg) and lungs (9.8 µg/mg) was observed in mink kits fed ALC. The RRR-α-tocopherol content in plasma and tissues depended on source and dose interaction and increased linearly with supplementation. In conclusion, the interaction between source and dose reveals a limitation in hydrolysis of ester bond in α-tocopheryl acetate in mink kits around weaning as the likely causative explanation for the higher response of ALC at the highest doses. Thus, considerable attention has to be paid to the source of α-tocopherol during weaning of mink kits fed a high dose of α-tocopherol.

scholarly journals A Tale of Two Metrics: The EPA Risk Quotient Approach versus the Delay in Population Growth Index for Determination of Pesticide Risk to Aquatic Species

2021 ◽  
Author(s):  
John D. Stark ◽  
John E. Banks
Keyword(s):  
Population Growth ◽  
Daphnia Pulex ◽  
Growth Index ◽  
Ceriodaphnia Dubia ◽  
Aquatic Species ◽  
Risk Quotient ◽  
Cladoceran Species ◽  
Generation Times ◽  
Species Being

Abstract The risk that two closely related insecticides, spinetoram and spinosad, posed to three Cladoceran species, Ceriodaphnia dubia, Daphnia pulex, and D. magna was determined using two approaches, the USEPA Risk Quotient method and the Delay in Population Growth Index (DPGI). Results of the RQ method showed that spinetoram posed a risk to all three species, but spinosad posed a risk only to C. dubia. The DPGI analysis showed that exposure to spinetoram resulted in populations of all three species being delayed > 3 generation times. Exposure to the LC50 and the lower 95% CL resulted in delayed populations while exposure to the upper 95% CL concentration of spinetoram resulted in no recovery of any of the three species over the course of the modeling exercise (88 d). Exposure to the lower and upper 95% Cl and the LC50 of spinosad resulted in C. dubia populations being delayed > 3 generations. D. pulex populations were not negatively affected after exposure to spinosad. D. magna populations were delayed > 3 generations, but only after exposure to the upper 95% Cl of spinosad. These results illustrate that although the EPA risk quotient method indicated that spinetoram posed a risk to all three species and that spinosad only posed a risk to C. dubia, the DPGI showed that D. magna would be negatively affected by spinosad and none of the three species would recover after exposure to the upper 95% CL of spinetoram. Because the DPGI uses the 95% Cl as well as the LC50 in its calculation and produces a measure of population growth and recovery or lack thereof, it provides more detailed information in terms of the potential risk of pesticides to populations than the RQ method.

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