Papers by Vinicius C Gonzalez
Research Square (Research Square), Oct 10, 2022
Declining bee populations diminish pollination services, damaging plant, and agricultural biodive... more Declining bee populations diminish pollination services, damaging plant, and agricultural biodiversity. One of the causes of this decline is the use of pesticides. Pesticides with glyphosate as an active ingredient are among the most used pesticides worldwide, being the most used in Brazil. This study determined the 24 and 48 hours LD50 (median lethal dose) of the herbicide glyphosate by ingestion, identi ed sublethal doses, and investigated its effects on the locomotion and behavior of Tetragonisca angustula workers. The LD50 found indicates that glyphosate is highly toxic to T. angustula. The doses applied, including concentrations found in nature and recommended dosage, caused death, motor changes (decreased speed and tremors), excessive self-cleaning, and disorientation (return to light and stop). These results suggest that this herbicide can negatively affect the pollination activity of T. angustula. Toxicity and sublethal effects evaluation of pesticides on bees contributes to a better understanding of the harmful effects on hives and to adopt strategies to reduce intoxication.
Dissertacao (mestrado)-Universidade Federal do Rio Grande, Programa de Pos-Graduacao em Ciencias ... more Dissertacao (mestrado)-Universidade Federal do Rio Grande, Programa de Pos-Graduacao em Ciencias Fisiologicas – Fisiologia Animal Comparada, Instituto de Ciencias Biologicas, 2008.
Ecotoxicology, Apr 29, 2023
Journal of Photochemistry and Photobiology B: Biology, 2016
The present work evaluated the infrared-A (IR-A) protective effect using a light-emitting diode (... more The present work evaluated the infrared-A (IR-A) protective effect using a light-emitting diode (LED) lamp against the cytotoxic effects of ultraviolet B radiation (UVB). Effects on cell viability (Trypan blue assay), DNA damage (comet assay), lipid peroxidation (FOX method), reactive oxygen species production and antioxidant capacity were analyzed in melan-a, a non-tumoral murine melanocytic cell line. To define the doses used in the interaction experiments between IR-A + UVB, dose/response curves were made after exposure to IR-A or UVB. The IR-A dose chosen was 0.8 J/cm 2 because this dose caused no significant inhibition of proliferation effects and viability decreased. For UVB exposure, a dose of 0.015 J/cm 2 , which showed a decrease in viable cell number by approximately 50% in relation to control until 72 h, was selected. For IR-A + UVB, cell proliferation recovery was showed, decreasing DNA damage and lipid peroxide content when compared to UVB alone. Besides, the results obtained for ROS and antioxidant capacity showed that the protection observed was probably not related to decreased oxidative stress. In conclusion, non-thermal IR-A was capable of protecting the melan-a cells from UVB induced damage.
Theriogenology, 2009
The sperm-egg interaction assay is a good predictor of the fertilizing potential of rooster semen... more The sperm-egg interaction assay is a good predictor of the fertilizing potential of rooster semen; the ability of chicken sperm to interact with the egg can be assessed by counting the number of holes in the inner perivitelline layer (IPVL) of a freshly laid egg. Although isolated IPVL can be stored for up to 24h, preservation of IPVL for prolonged intervals in liquid nitrogen would facilitate the sperm-egg interaction assay. The objective of this study was to adapt the technique of vitrifying swine oocytes for use with the IPVL. Our hypothesis was that vitrification would not alter the ability of the membrane to bind sperm; therefore, there would be no difference between vitrified and fresh IVPL in the number of hydrolysis holes made by sperm. Our hypothesis was supported; there were no differences in the mean+/-SEM number of holes made by the same sample of sperm in vitrified and in fresh membranes (146.0+/-17.7 holes/mm(2) IPVL and 159.5+/-17.7 holes/mm(2) IPVL, respectively, P>0.05; n=123 IVPLs tested). Furthermore, 80% of frozen-thawed membranes were recovered intact. Because vitrification did not significantly change the ability of membranes to bind sperm, vitrified membranes can be safely used for the sperm-egg interaction assay. Vitrified IVPL would ensure availability for sperm evaluation and facilitate wide distribution of IPVL, enabling assays to be conducted even in the absence of facilities or expertise to prepare membranes.
Photochemistry and Photobiology, 2009
This paper analyzes the influence of infrared radiation (IR) on regeneration, after autotomy of l... more This paper analyzes the influence of infrared radiation (IR) on regeneration, after autotomy of limb buds of Neohelice granulata and consequently the time molt. Eyestalks were ablated to synchronize the start of molt. Afterward, animals were autotomized of five pereopods and divided into control and irradiated groups. The irradiated group was treated for 30 min daily until molt. Limb buds from five animals of days 4, 16 and 20 were collected and histological sections were made from them. These sections were photographed and chitin and epithelium content measured. Another group was made, and after 15 days limb buds were extracted to analyze mitochondrial enzymatic activity from complex I and II. The irradiated group showed a significant reduction in molt time (19.38 ± ± 1.22 days) compared with the control group (32.69 ± ± 1.57 days) and also a significant increase in mitochondrial complex I (388.9 ± ± 27.94%) and II (175.63 ± ± 7.66%) in the irradiated group when compared with the control group (100 ± ± 17.90; 100 ± ± 7.82, respectively). However, these effects were not acompanied by histological alterations in relation to chitin and epithelium. This way, it was possible to demonstrate that IR increases complex I and II activity, reduces the time molt and consequently increases the appendage regeneration rate.
Photochemistry and Photobiology, 2015
To determine the chronic skin effects caused by the interaction of infrared and ultraviolet B rad... more To determine the chronic skin effects caused by the interaction of infrared and ultraviolet B radiations, male Rattus norvegicus (Wistar) (2 months old) were exposed for 15 days to infrared radiation (600-1500 nm, with a peak at 1000 nm, n = 12) for 30 min (1080 J cm(-2) ) (IRo); to ultraviolet B radiation (peak emission at 313 nm, n = 9) for 90 min (55.08 J cm(-2) ) (UVB); to infrared radiation followed after 90 min by ultraviolet B (n = 6) (IRUVB) and to ultraviolet B followed after 90 min by infrared radiation (n = 9) (UVBIR). Skin samples were collected and histopathological analysis showed the presence of acanthosis, parakeratotic and orthokeratotic hyperkeratosis, intraepidermal pustules, keratin pearls, detachment of epidermis, collagen necrosis, inflammatory infiltrate, vasodilation, basal cell vacuolization and superficial dermis degeneration both in UVB and UVBIR treatments. IRUVB animals showed the same characteristics as above except for parakeratotic hyperkeratosis, keratin pearls and superficial dermis degeneration. To conclude, infrared radiation exposure after ultraviolet B irradiation increases skin damage without protecting the tissue, while infrared radiation exposure before ultraviolet B irradiation showed a protective effect against ultraviolet skin damage.
The sperm-egg interaction assay is a good predictor of the fertilizing potential of rooster semen... more The sperm-egg interaction assay is a good predictor of the fertilizing potential of rooster semen; the ability of chicken sperm to interact with the egg can be assessed by counting the number of holes in the inner perivitelline layer (IPVL) of a freshly laid egg. Atlhough isolated IPVL can be stored for up to 24 h, preservation of IPVL for prolonged intervals in liquid nitrogen would facilitate the sperm-egg interaction assay. The objective of this study was to adapt the technique of vitrifying swine oocytes for use with the IPVL. Our hypothesis was that vitrification would not alter the ability of the membrane to bind sperm; therefore, there would be no difference between vitrified and fresh IVPL in the number of hydrolysis holes made by sperm. Our hypothesis was supported; there were no differences in the mean AE SEM number of holes made by the same sample of sperm in vitrified and in fresh membranes (146.0 AE 17.7 holes/mm 2 IPVL and 159.5 AE 17.7 holes/mm 2 IPVL, respectively, P > 0.05; n = 123 IVPLs tested). Furthermore, 80% of frozen-thawed membranes were recovered intact. Because vitrification did not significantly change the ability of membranes to bind sperm, vitrified membranes can be safely used for the sperm-egg interaction assay. Vitrified IVPL would ensure availability for sperm evaluation and facilitate wide distribution of IPVL, enabling assays to be conducted even in the absence of facilities or expertise to prepare membranes.
El artículo relata los resultados de una investigación piloto con niños mediante "O jogo dos lanc... more El artículo relata los resultados de una investigación piloto con niños mediante "O jogo dos lances" ( El juego de las apuestas). El objetivo del juego, además de divertir, es convertirse en un medio para describir las aspiraciones y expectativas de un grupo estudiantes de estrato social bajo. Los resultados son interesantes pues apuntan tanto a la fuerte socialización en términos de demandas de derechos y expectativas, a pesar de la corta edad, y de la incidencia de la variable género sobre los resultados. Los datos indican que estamos en un mundo en el cual la cumbre de las preferencias es ocupado por la salud (niñas) y renta (niños). Se agregan las preferencias por las tecnologías, por los juegos electrónicos y la tecnología celular. Los datos indican un mundo de razones prácticas moldados por necesidades donde, las formas tradicionales del juego, parecen haber perdido parcela significativa de su demanda garantida.
Photochemistry and Photobiology, 2009
This paper analyzes the influence of infrared radiation (IR) on regeneration, after autotomy of l... more This paper analyzes the influence of infrared radiation (IR) on regeneration, after autotomy of limb buds of Neohelice granulata and consequently the time molt. Eyestalks were ablated to synchronize the start of molt. Afterward, animals were autotomized of five pereopods and divided into control and irradiated groups. The irradiated group was treated for 30 min daily until molt. Limb buds from five animals of days 4, 16 and 20 were collected and histological sections were made from them. These sections were photographed and chitin and epithelium content measured. Another group was made, and after 15 days limb buds were extracted to analyze mitochondrial enzymatic activity from complex I and II. The irradiated group showed a significant reduction in molt time (19.38 ± ± 1.22 days) compared with the control group (32.69 ± ± 1.57 days) and also a significant increase in mitochondrial complex I (388.9 ± ± 27.94%) and II (175.63 ± ± 7.66%) in the irradiated group when compared with the control group (100 ± ± 17.90; 100 ± ± 7.82, respectively). However, these effects were not acompanied by histological alterations in relation to chitin and epithelium. This way, it was possible to demonstrate that IR increases complex I and II activity, reduces the time molt and consequently increases the appendage regeneration rate.
Theriogenology, 2009
The sperm-egg interaction assay is a good predictor of the fertilizing potential of rooster semen... more The sperm-egg interaction assay is a good predictor of the fertilizing potential of rooster semen; the ability of chicken sperm to interact with the egg can be assessed by counting the number of holes in the inner perivitelline layer (IPVL) of a freshly laid egg. Although isolated IPVL can be stored for up to 24h, preservation of IPVL for prolonged intervals in liquid nitrogen would facilitate the sperm-egg interaction assay. The objective of this study was to adapt the technique of vitrifying swine oocytes for use with the IPVL. Our hypothesis was that vitrification would not alter the ability of the membrane to bind sperm; therefore, there would be no difference between vitrified and fresh IVPL in the number of hydrolysis holes made by sperm. Our hypothesis was supported; there were no differences in the mean+/-SEM number of holes made by the same sample of sperm in vitrified and in fresh membranes (146.0+/-17.7 holes/mm(2) IPVL and 159.5+/-17.7 holes/mm(2) IPVL, respectively, P>0.05; n=123 IVPLs tested). Furthermore, 80% of frozen-thawed membranes were recovered intact. Because vitrification did not significantly change the ability of membranes to bind sperm, vitrified membranes can be safely used for the sperm-egg interaction assay. Vitrified IVPL would ensure availability for sperm evaluation and facilitate wide distribution of IPVL, enabling assays to be conducted even in the absence of facilities or expertise to prepare membranes.
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Papers by Vinicius C Gonzalez