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61.
Vinicius Araújo Armelin Victor Hugo da Silva Braga Mariana Teodoro Teixeira Francisco Tadeu Rantin Luiz Henrique Florindo Ana Lúcia Kalinin 《Fish physiology and biochemistry》2016,42(4):1213-1224
The baroreflex is one of the most important regulators of cardiovascular homeostasis in vertebrates. It begins with the monitoring of arterial pressure by baroreceptors, which constantly provide the central nervous system with afferent information about the status of this variable. Any change in arterial pressure relative to its normal state triggers autonomic responses, which are characterized by an inversely proportional change in heart rate and systemic vascular resistance and which tend to restore pressure normality. Although the baroreceptors have been located in mammals and other terrestrial vertebrates, their location in fish is still not completely clear and remains quite controversial. Thus, the objective of this study was to locate the baroreceptors in a teleost, the Colossoma macropomum. To do so, the occurrence and efficiency of the baroreflex were both analyzed when this mechanism was induced by pressure imbalancements in intact fish (IN), first-gill-denervated fish (G1), and total-gill-denervated fish (G4). The pressure imbalances were initiated through the administration of the α1-adrenergic agonist phenylephrine (100 µg kg?1) and the α1-adrenergic antagonist prazosin (1 mg kg?1). The baroreflex responses were then analyzed using an electrocardiogram that allowed for the measurement of the heart rate, the relationship between pre- and post-pharmacological manipulation heart rates, the time required for maximum chronotropic baroreflex response, and total heart rate variability. The results revealed that the barostatic reflex was attenuated in the G1 group and nonexistent in G4 group, findings which indicate that baroreceptors are exclusively located in the gill arches of C. macropomum. 相似文献
62.
It had been found earlier that the chloronicotinyl insecticide thiacloprid (as the 480 g litre(-1) SC Calypso) poses a favourably low toxicity hazard to the honeybee, Apis mellifera L. As with pyrethroids, the metabolization of chloronicotinyl compounds involves monooxygenases, which are known to be inhibited by some ergosterol biosynthesis inhibitor (EBI) fungicides potentially co-applied with these insecticides. The potential synergistic enhancement of the toxicity of thiacloprid to honeybees when co-applied with such fungicides was therefore studied under laboratory and semi-field conditions. Fungicides of other chemical classes were also examined for synergistic potential to reveal other metabolic interactions. In the laboratory, only a slight synergistic effect was observed with the anilinopyrimidine fungicide examined, while a significant enhancement of thiacloprid toxicity to honeybees was found with EBI fungicides. In three tunnel tests conducted under different environmental conditions to simulate field exposure, no increased mortality was observed when honeybees were directly sprayed with thiacloprid (Calypso) alone or in combination with the EBI fungicide tebuconazole (250 g litre(-1) EW, Folicur). There was also no synergized reduction in the foraging intensity on the treated crop. In general, the foraging intensity decreased after thiacloprid treatment but was restored within 24-48 h. The hive vitality was not affected by either thiacloprid or its tank mix with tebuconazole. Our results suggest that, at the recommended use rates, thiacloprid poses a negligible lethal risk to honeybees when applied either alone or in tank mixes with fungicides of various chemical classes. 相似文献
63.
Di Provvido Andrea Di Teodoro Giovanni Muuka Geoffrey Marruchella Giuseppe Scacchia Massimo 《Tropical animal health and production》2018,50(1):223-228
Tropical Animal Health and Production - Contagious bovine pleuropneumonia (CBPP) is a severe infectious disease caused by Mycoplasma mycoides subsp. mycoides. The peculiar pathological features of... 相似文献
64.
Esposito F Fogliano V Cardi T Carputo D Filippone E 《Journal of agricultural and food chemistry》2002,50(6):1553-1561
This paper reports the results of chemical analyses performed on two distinct groups of new potato genotypes. The first group contained five clones transformed with the gene ech42 encoding for an endochitinase. The second included 21 interspecific hybrids between the cultivated potato Solanum tuberosum and the wild species S. commersonii, obtained either by somatic fusion or by sexual hybridization. Tubers from transgenic plants were analyzed for several morphological and biochemical parameters to ascertain the substantial equivalence between the transgenic genotypes and the original cultivar Désirée. The interspecific hybrids were analyzed for the same parameters in order to identify genotypes with novel improved chemical characteristics and with low levels of glycoalkaloids deriving from the wild species and potentially hazardous to human health. For transgenic tubers, the results provided evidence that indicates the substantial equivalence between the transgenic genotypes and the cultivated control for the considered traits. The results suggest that chitinase gene insertion did not alter other metabolic pathways of potato tubers and did not cause unintentional pleiotropic effects. As far as interspecific hybrids are concerned, wide variability for all of the parameters analyzed was found. For some useful traits (e.g., soluble solids and proteins, dry matter content) the interspecific hybrids performed better than both the cultivated control and the wild species. In a number of genotypes, glycoalkaloid levels were close to or lower than those of the control varieties, suggesting that selection for low glycoalkaloid content is possible. The results also indicated that glycoalkaloids from S. commersonii may be lost rapidly. Indeed, some hybrids were found to have the same glycoalkaloid profile as S. tuberosum. Finally, the results showed that among the parameters considered, glycoalkaloid content is the most sensitive to variation. Therefore, glycoalkaloid determination should be used for routine control of genotypes produced by interspecific hybridization. 相似文献
65.
Lawrence DJ Eke VR Elphic RC Feldman WC Funsten HO Prettyman TH Teodoro LF 《Science (New York, N.Y.)》2011,334(6059):1058-105c
Based on a study of high-energy epithermal (HEE) neutrons in data from the Lunar Exploration Neutron Detector (LEND) on NASA's Lunar Reconnaissance Orbiter (LRO), the background from HEE neutrons is larger than initially estimated. Claims by Mitrofanov et al. (Reports, 22 October 2010, p. 483) of enhanced hydrogen abundance in sunlit portions of the lunar south pole and quantitative hydrogen concentration values in south pole permanently shaded regions are therefore insufficiently supported. 相似文献
66.
Puglisi Edoardo Zaccone Claudio Cappa Fabrizio Cocconcelli Pier Sandro Shotyk William Trevisan Marco Miano Teodoro M. 《Biology and Fertility of Soils》2014,50(5):815-826
Biology and Fertility of Soils - Peatlands are archives of extreme importance for the assessment of past ecological, environmental and climatic changes. The importance as natural archives is even... 相似文献
67.
Luara Castilho Pereira Leonardo Balbinot Marcelle Teodoro Lima Julieta Bramorski Kelly Cristina Tonello 《林业研究》2022,(2):543-552
Although forests play important roles in the hydrological cycle,there is little information that relates the water retention capacity of litter in areas under passive restoration,especially in Cerrado savannas.This study relates litter levels to water holding capacity and effective water retention among forest fragments under different passive restoration stages:46,11,and 8 years to better understand litter hydrological functions in the Cerrado.Water retention c apacity and effective water reten... 相似文献