902 resultados para Melatonin -- Physiological effect


Relevância:

80.00% 80.00%

Publicador:

Relevância:

80.00% 80.00%

Publicador:

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This chapter reviews studies on the effects of mycotoxins on embryonic and fetal development, especially those toxins that are global food and feed contaminants. The toxins discussed include aflatoxin produced by Aspergillus flavus and A. parasiticus, ochratoxin which is produced by Aspergillus species particularly A. ochraceus as well as Penicillium verrucosum, ergot alkaloids produced by Claviceps spp., and the Fusarium toxins (fumonisins, deoxynivalenol [vomitoxin], and zearalenone). These toxins have been shown to be teratogenic and/or embryotoxic in different animal bioassays. The implications of toxicity on embryogenesis, and the progress of research on these mycotoxins, are also examined.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

This study attempted to determine if an excessive amount of 1,1,1 - Trichloroethane was released into the air, the acute effects of exposure and the cause(s) of excessive use. The types of degreasing equipments which were tested in this study are straight vapor and the vapor spray machines. The instruments utilized to obtain the data for this study are Gastech Haline Detector, Organic Vapor Monitor Badge and Personal Sampling Pump. Readings were taken on three different tanks. The data accumulated by this study were obtained during actual cleaning operation. During testing, increased exposure was detected due to exceeding the rate of removal, downward drafts were blowing right over the top of a degreaser and, in some cases, poor general ventilation caused solvent vapor to be blown out of the tank and into the workers' breathing zone, affecting excessive vapor drag out and solvent loss. The results show that, since the characteristics of solvent 1,1,1 - Trichloroethane are well suited to vapor degreasing requirements, by using proper procedures and maintenance, 1,1,1 - Trichloroethane emission during vapor degreasing can be controlled at levels well below the industrial hygiene standard established by OSHA for safe and healthful conditions.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Plants that develop under foliar shade encounter both low photosynthetically active radiation (PAR) and low red to far red ratios (R:FR). Both of these factors are important in determining developmental responses to shade. Papaya (Carica papaya L.) seedlings grown under filtered shade (low PAR and low R:FR) were compared with seedlings grown under neutral shade (low PAR with R:FR similar to that of full sunlight), and high light (moderate PAR with R:FR similar to that of full sunlight). The results indicated that papaya exhibits a light seeking strategy as evidenced by morphological and anatomical differences between treatments. Based on past research the results also indicate shade developmental responses in papaya to be phytochrome mediated.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The peaches and nectarines are highly appreciated by consumer, but it is climacteric fruits, with availability in the market in small time. It is necessary to invest to obtain genotypes with fruit quality and small perishability or that it presente less physiological disorders after storage. The aims of this work were i) to evaluate the genetic divergence among 40 peach and nectarine trees genotypes based on postharvest quality and select posible parents; ii) to evaluate the susceptibility to chilling injury in peaches and nectarines after cold storage; iii) to evaluate divergence of peaches and nectarines on the basis in the susceptibility for chiling injury and select superior genotypes; iv) evaluate the correlations between quality and susceptibility to chilling injury of peaches and nectarines v) select parents with the combination of lower susceptibility to chilling injury and higher quality fruit. The study was carried out in EEAD-CSIC, Zaragoza - Spain, during the production cycle 2013/2014. A total of 40 peaches and nectarines genotypes from germplasm collection were evaluated. The quality characteristics as flesh firmness, total soluble solids, titratable acidity, pH, rippining index and flesh color parameters were evaluated. The fruits were submitted to cold storage at 0 °C and 5 °C, with 95% average relative humidity. The evaluations were after 14 and 28 days, it being observed the presence of symptoms, such as wooliness through mealiness, flesh grainy, leatheriness and flesh color changes, through browning, bleeding and off flavor. As a selection parameter was adopted 20% of genotypes that had a higher frequency of superiority for quality characteristics, susceptibility to chilling injury and the combining of both. For quality characteristic presented greater divergence the ‘Queen Giant’, ‘Sudanel Blanco’ and ‘Borracho de Jarque’. Based on the quality the eight genotypes were selected, ‘Andross’, ‘San Jaime’, ‘San Lorenzo’, ‘Borracho de Jarque’, ‘Sudanell 1’, ‘Carson’, ‘Baby Gold 6’ and ‘Stanford’. All genotypes studied exhibited susceptibility to one or more symptoms caused by cold storage during 28 days, independent of temperature. For 14 days, the ‘Baby Gold 6’, ‘Flavortop’ and ‘Queen Giant’ genotypes did not show any physiological disorder caused by cold. In general, the temperature of 0 °C favored fruit postharvest conservation, it have a lower incidence and severity of symptoms caused by cold storage. The storage for 14 days contributed for the lower incidence of damage in the genotypes fruits studied. For 14 days, with both temperatures, it was observed divergence for ‘Queen Giant’, ‘Sudanell Blanco’, ‘Baby Gold 6’ ‘GF3’, ‘Baby Gold 8’, ‘Campiel’ and ‘Campiel Rojo’ genotypes. For 28 days, in the 5 °C condition, ‘Queen Giant’, ‘Big Top’, ‘Flavortop’ and ‘Redhaven’ genotypes were divergents. Based on susceptibility to chilling injury at 0 °C, the eight genotypes were selected, it being these, ‘Queen Giant’, ‘Keimoes’, ‘Flavortop’, ‘Big Top’, 'Redhaven', 'Sudanell 3', 'Bonet I' and ‘Carson’. The quality parameters as rippining index, soluble solids, firmness and titratable acidity presented correlation among them. These, also it had correlation with woolines and bowning, what it indicate that fruits with more ripening can have this symptoms more easily. The browning, mealiness, flesh grainy and off flavor variables were correlationed with the time period and temperartures, what it confirm that these symptoms are the main disorders caused by cold storage. The quality characteristics together susceptibility to chilling injury allowed selected ‘Baby Gold 6’, ‘Sarell’, ‘Keimoes’, ‘GF3’ ‘San Jaime’, ‘Big Top’, ‘Sudanell 1’, ‘Carson’, ‘Baby Gold 8’, and ‘San Lorenzo’ genotypes.