Search results for "ultraviolet light"
showing 10 items of 51 documents
Kestrels prefer scent marks according to species and reproductive status of voles
1999
We have previously documented that European kestrels (Falco tinnunculus L.) are attracted to the scent marks of small rodents in the presence of ultraviolet light (UV) but not visible light (VL). I...
Extensive osteonecrosis of the maxilla caused by bisphosphonates: Report of a rare case
2019
Bisphosphonates are drugs indicated for the treatment of bone metabolic diseases or malignant hypercalcemia. They are generally well-tolerated drugs, however, recent reports have described osteonecrosis of the jaw bones as a potentially serious complication related to the long-term use of these drugs. We report a case of severe osteonecrosis in a 52-years-old white woman that was taking bisphosphonates (zoledronic acid and alendronate) for the management of osteoporosis. Following a long exposure to these drugs and after being subjected to multiples exodontias, developed bisphosphonate-related osteonecrosis of the jaw compromising the whole maxilla and that extended toward the base of skull…
The biology of color
2017
In living color Animals live in a colorful world, but we rarely stop to think about how this color is produced and perceived, or how it evolved. Cuthill et al. review how color is used for social signals between individual animals and how it affects interactions with parasites, predators, and the physical environment. New approaches are elucidating aspects of animal coloration, from the requirements for complex cognition and perception mechanisms to the evolutionary dynamics surrounding its development and diversification. Science , this issue p. eaan0221
Response of membrane-bound ATPase of Micrococcus luteus to heat and ultraviolet light.
1976
It is shown that the properties of ATPase (EC 3.6.1.3) of Micrococcus luteus depend only to some extent on the state of the membrane to which it is attached. Its interaction with the membrane appears to be largely controlled by polar forces. It is shown, however, that the UV-sensitivity of the membrane-bound ATPase is also significantly influenced by the state of membrane lipids.
Upper lip malignant neoplasms : a study of 59 cases
2011
Objectives: To present the demographic data, clinico-pathologic features and therapeutic outcome of a series of upper lip malignancies. Study Design: Retrospective study at a single Cancer Institution in Mexico City during a 14-year period. Results: There were 59 cases, (30 males and 29 females); age range: 14 to 106 years (mean: 73 yr.). Antecedents of ultraviolet light and tobacco exposure were found in 20 (33.9%) and 16 cases (27%) respectively. There were 35 squamous cell carcinomas (59.3%), 19 basal cell carcinomas (32.2%) and one case each (1.7%) of adenocarcinoma NOS, adenoid cystic carcinoma, angiosarcoma, Merkel cell carcinoma and melanoma. There were 14 cases in stage I (23.7%), 1…
Kinetics of gamma-H2AX focus formation upon treatment of cells with UV light and alkylating agents.
2008
Histone H2AX is rapidly phosphorylated in response to DNA double-strand breaks (DSBs) induced by ionizing radiation (IR). Here we show that DNA damage induced by alkylating agents [methyl methanesulfonate (MMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)] and ultraviolet light (UV-C) leads to a dose and time dependent accumulation of phosphorylated H2AX (gamma-H2AX). Time course experiments revealed that the number of gamma-H2AX foci reached peak levels 8 hr after MMS or MNNG treatment and declined to almost control values within 24 hr after exposure. Upon UV-C treatment, a biphasic response was observed with a maximum 12 hr after treatment. In 43-3B cells deficient in nucleotide excisi…
Efficient ultraviolet-light energy dissipation by an aromatic ketone.
2010
Experimental evidence on the efficiency of 2,2'4,4'-tetramethoxybenzil for UV-light energy dissipation is provided. This non-phenolic aromatic ketone has a low energy triplet which quickly decays to the ketone ground state, thus avoiding the generation of undesirable reactive species. El Moncef, Abdelkarim, elmonab@alumni.uv.es ; Cuquerella Alabort, Maria Consuelo, Chelo.Cuquerella@uv.es ; Zaballos Garcia, Elena, Elena.Zaballos@uv.es ; Ramirez de Arellano Sanchez, Maria del Carmen, Carmen.Ramirezdearellano@uv.es ; Stiriba, Salah Eddine, Salah.Stiriba@uv.es ; Perez Prieto, Julia, Julia.Perez@uv.es
Detecting rottenness caused by Penicillium genus fungi in citrus fruits using machine learning techniques
2012
Penicillium fungi are among the main defects that may affect the commercialization of citrus fruits. Economic losses in fruit production may become enormous if an early detection of that kind of fungi is not carried out. That early detection is usually based either on UltraViolet light carried out manually. This work presents a new approach based on hyperspectral imagery for defect segmentation. Both the physical device and the data processing (geometric corrections and band selection) are presented. Achieved results using classifiers based on Artificial Neural Networks and Decision Trees show an accuracy around 98%; it shows up the suitability of the proposed approach.
Can ultraviolet cues function as aposematic signals?
2001
The fact that birds are sensitive to ultraviolet light (UV, 320–400 nm) has been largely ignored by previous studies of aposematism. Therefore, in the present article we investigated whether great tits preferred ultraviolet-reflecting colors compared to colors without UV reflection and whether UV cues alone could function as aposematic signals. We were able to manipulate prey visibility in UV light by changing the UV reflectance of prey items as well as altering the lighting conditions. In order to perform a preference experiment we used three pairs of colors (green UV vs. green, gray UV vs. gray, yellow UV vs. yellow) on a black background. The birds ate both UV types equally for all three…
Photocatalytic oxidation mechanism of benzonitrile in aqueous suspensions of titanium dioxide
2007
Abstract The photocatalytic oxidation of benzonitrile was carried out in aqueous suspensions (pH 11) of commercial polycrystalline TiO 2 (Merck and Degussa P25) irradiated by ultraviolet light. The rate of decomposition was dependent on the concentration of benzonitrile and followed a pseudo-first order kinetics. The complete mineralization of a 0.70 mM benzonitrile solution was achieved in ca. 8 h by using TiO 2 Degussa P25, whereas the substrate was only partially mineralized even after 14 h of irradiation in the presence of TiO 2 Merck. The final oxidation products were carbonate and nitrate. The appearance and the evolution of organic and inorganic intermediate species were also investi…