Denise Schmidt

The anesthetic efficacy of eugenol and the essential oils of Lippia alba and Aloysia triphylla in post-larvae and sub-adults of Litopenaeus vannamei (Crustacea, Penaeidae)

The aim of this study was to evaluate the anesthesia induction and recovery times of sub-adult and post-larvae white shrimp (Litopenaeus vannamei) that were treated with eugenol and the essential oils (EOs) from Lippia alba and Aloysia triphylla. Oxidative stress parameters in the hemolymph of this species were also analyzed. The concentrations of eugenol, A. triphylla EO and L. alba EO recommended for anesthesia were 200, 300 and 750 μL L(-1) for sub-adults and 175, 300 and 500 μL L(-1) for post-larvae, respectively. The concentrations studied during the transport of sub-adults were between 20 and 50 μL L(-1) eugenol, 20-30 μL L(-1)A. triphylla EO and 50 μL L(-1)L. alba EO. For post-larvae, the optimal concentrations for transport were 20 μL L(-1) eugenol and between 20 and 50 μL L(-1)A. triphylla EO. The white shrimp sub-adults that were exposed to A. triphylla EO (20 μL L(-1)) showed increases in their total antioxidant capacities (150%), catalase (70%) and glutathione-S-transferase (615%) activity after 6 h. L. alba EO (50 μL L(-1)) and eugenol (20 μL L(-1)) also increased GST activity (1292 and 1315%) after 6 h, and eugenol (20 μL L(-1)) decreased the total antioxidant capacity (100%). Moreover, concentrations above 30 μL L(-1) for the EOs of A. triphylla and L. alba and 20 μL L(-1) eugenol were effective at inducing anesthesia and improving the antioxidant system against reactive oxygen species (ROS) after 6 h.

Participation of the GABAergic system in the anesthetic effect of Lippia alba (Mill.) N.E. Brown essential oil

The objective of this study was to identify the possible involvement of the GABAergic system in the anesthetic effect of Lippia alba essential oil (EO). We propose a new animal model using silver catfish (Rhamdia quelen) exposed to an anesthetic bath to study the mechanism of action of EO. To observe the induction and potentiation of the anesthetic effect of EO, juvenile silver catfish (9.30 ± 1.85 g; 10.15 ± 0.95 cm; N = 6) were exposed to various concentrations of L. alba EO in the presence or absence of diazepam [an agonist of high-affinity binding sites for benzodiazepinic (BDZ) sites coupled to the GABAA receptor complex]. In another experiment, fish (N = 6) were initially anesthetized with the EO and then transferred to an anesthetic-free aquarium containing flumazenil (a selective antagonist of binding sites for BDZ coupled to the GABAA receptor complex) or water to assess recovery time from the anesthesia. In this case, flumazenil was used to observe the involvement of the GABA-BDZ receptor in the EO mechanism of action. The results showed that diazepam potentiates the anesthetic effect of EO at all concentrations tested. Fish exposed to diazepam and EO showed faster recovery from anesthesia when flumazenil was added to the recovery bath (12.0 ± 0.3 and 7.2 ± 0.7, respectively) than those exposed to water (9.2 ± 0.2 and 3.5 ± 0.3, respectively). In conclusion, the results demonstrated the involvement of the GABAergic system in the anesthetic effect of L. alba EO on silver catfish.

Could the essential oil of Lippia alba provide a readily available and cost-effective anaesthetic for Nile tilapia (Oreochromis niloticus)?

Abstract We report the optimal concentration of the essential oil of Lippia alba (EOLA) for the induction and recovery of anesthesia in Nile tilapia (Oreochromis niloticus) during handling. Groups of 10 juveniles were separately subjected to a concentration of EOLA: 0 (control group), 10, 20, 50, 100, 200, 300, or 500 µL L-1. The plasma cortisol levels were significantly decreased in anesthetized fish 4 h after stress of handling. The plasma glucose levels were significantly increased 1 and 4 h after stress of handling in fish exposed to EOLA. Sensory analysis showed that tasters did not detect differences through a blind test in fillet taste and odor between exposed and non-exposed fish. The ideal concentration to promote the best anesthesia and recovery times and to reduce plasma cortisol 4 h after handling is 500 µL L-1.

Using the essential oil of Aloysia triphylla (L'Her.) Britton to sedate silver catfish (Rhamdia quelen) during transport improved the chemical and sensory qualities of the fish during storage in ice.

UNLABELLED Exposure of silver catfish to 40 μL/L of the essential oil of Aloysia triphylla (AT) during in vivo transport delayed the onset and resolution of rigor mortis as well as the degradation of IMP into HxR compared to the control. The fish that were treated with 30 or 40 μL/L of AT received lower sensory demerit scores after 10 d of storage in ice compared to the control, and the fish that were treated with 40 μL/L of AT had a longer sensory shelf life than did the control. These results indicated that using AT as a sedative in the water in which the silver catfish were transported extended their freshness and increased their shelf life during refrigerated storage. PRACTICAL APPLICATION Interest in natural anesthetics, such as Aloysia triphylla, has increased in the field of commercial aquaculture because they reduce the number of fish lesions acquired during capture, handling, and transportation. Fish sedated with the essential oil of A. triphylla at 40 μL/L during transport before slaughter exhibited a delay in the loss of freshness and an increased shelf life in ice. In addition to improving animal welfare before slaughter, the essential oil appears to be a promising product for improving fish conservation in the food industry.

Eficiência do uso da radiação solar por plantas Ilex paraguariensis A. St. Hil. cultivadas sob sombreamento e a pleno sol

The efficiency of conversion of the solar radiation in biomass is a variable frequently used in models of simulation the culture growth, because the biomass production is related with the efficiency of which a plant converts radiant energy in chemistry, given by the process of the photosynthesis. The objective of this work was to determine the efficiency of conversion of the photosynthetically active and intercepted solar radiation (RFAi) in Ilex paraguariensis biomass, cultivated in consortium (Ilex paraguariensis A. St. Hil. E Pinus elliottii Engelm) and single. For so much, it was determined the photosynthetically active and intercepted solar radiation (RFAi), the index of leaf area and the biomass dries of the seedlings, being then, the efficiency of conversion of RFAi in biomass dries of the cultivated in consortium and single. For a same radiation value RFAi, is obtained larger efficiency of use of the radiation in the accumulation in matter dries when Ilex paraguariensis is cultivated in consortium. The conversion efficiency (eb) of biomass total drought of Ilex paraguariensis plants in relation to the amount of the photosynthetically active and intercepted solar radiation (RFAi) accumulated is of 0.83 g MJ-1 in the system consortium and of 0.23 g MJ-1 in the single system. In spite of that, the production of aerial biomass for plant was larger in the single system.

Influência do espaçamento nas características energéticas de espécies arbóreas em plantios de curta rotação

This study aimed to determine the higher heating value (PCS) of trees and basic density weighted (ρb pond) of wood of Acacia mearnsii De Wild, Eucalyptus grandis W. Hill ex Maiden, Mimosa scabrella Benth and Ateleia glazioviana Baill distributed in different spacings in planting: 2.0 x 1.0 m, 2.0 x 1.5 m, 3.0 x 1.0 m and 3.0 x 1.5 m, at ages of 1 and 3 years. The study was conducted in an experiment in the city of Frederico Westphalen, State of RS, in experimental design of randomized complete block design with three replications in a split plots. The determination of the PCS of the trees was made from the weighting of the values obtained in each compartment (wood, bark, twig and leaf) using calorimeter bomb. The determination of ρb pond was performed from the weighting of the values recorded on discs collected at different positions along the stem, using the method of hydrostatic balance and dry mass. The PCS of all species in the first year after planting was higher than the third year, highlighting the Acacia mearnsii with the highest averages. The ρb pond had no systematic trend of increase or decrease over time, and the species Acacia mearnsii and Ateleia glazioviana showed the highest values. The different planting spacings did not induce the change in PCS and ρb pond in the species studied and it was not verified a positive or negative systematic trend in relation to the living space provided by the spacing.

Eficiência de conversão da radiação fotossinteticamente ativa interceptada em fitomassa de mudas de eucalipto

The biomass production is function of the conversion efficiency of the photosynthetically active radiation intercepted (PARi), varying according to the conditions in which plants are cultivated. Therefore the objective of this work was to quantify the function of the efficiency of conversion of the photosynthetically active radiation intercepted (PARi) in dry biomass - eb - , of seedlings of Eucalyptus grandis W. Hill ex Maiden (eucalyptus) when submitted to different sizes of tubes and densities of plants. Therefore, an experiment was conducted in randomized blocks to study seedlings production in two sizes of tubes (small and medium) and two densities of plants in the tray (high with 100% of occupation of the tray and average with 50% of occupation), where PARi, the index of foliar area and the total dry biomass of the seedlings were evaluated. The volume of the tube did not interfere in the efficiency values, but, the density of plants did because the index of foliar area is the one which determines such value. The ab was of 7.33 g.MJ-1 for medium and small tube in high density and of 3.26 g.MJ-1 for medium and small tube in medium density.

Produção de sementes de alface em cultivo hidropônico

Lettuce seeds of Deyse and Regina cultivars were produced in greenhouse, in hydroponic system, with excelents rendiments per plant and seed quality, when compared to conventional systems, of parcels in field. This results recommend studies in lettuce seeds production in greenhouse.

Qualidade fisiológica de sementes de alface submetidas a diferentes temperaturas na presença e ausência de luz

The experiment on the different types of lettuce seeds, and the effects of light and temperature occured in the Didactic Laboratory of Researches in Seeds, of Santa Maria Federal University, Brazil. Elisa, Regina and Rainha de Maio, were selected and tested under the tempreatures of 20°C; 25°C; 30°C; 35°C; 20-30°C, for establish a bifactorial experiment separately conducted, with and without light. The substratum was used on paper in gerbox, with four repetitions of 100 seeds for treatment. The selected light conditions were 8 hours of light and 16 hours of darkness, for every day. For the condition without light an aluminum paper was placed over the gerboxes. The evaluations of plant size and first germination were made in the fourth day and the final percentage of germination, in the seventh day. It was observed that without light, the lower the temperature the more plants germanated. When tested with light it was found that with Elisa and Regina, the tempurature had no effect except at 35o, in which germination was impeded. In conclusion, exist influence of lettuce genotypes in physiological quality seeds. The light is a limiter factor in germination. Within the tested temperatures, it was found that 20oC was the best for the three cultivars. In presence of light, the plants initial development occured within a wide strip of temperature (20°C to 30°C). Temperature of 35°C cause secondary dormancy in lettuce seeds.O trabalho foi conduzido no Laboratorio Didatico e de Pesquisas em Sementes da Universidade Federal de Santa Maria, com o objetivo de avaliar o efeito da temperatura e da luz sobre a germinacao e vigor das plântulas de alface. Foram utilizados os cultivares Elisa, Regina e Rainha de Maio e submetidos aos tratamentos de temperatura a 20; 25; 30; 35°C e 20-30°C, estabelecendo um experimento bifatorial (3x5), conduzido na presenca e ausencia de luz. Utilizou-se o substrato sobre papel em caixas plasticas de germinacao, sob o delineamento inteiramente casualizado, com quatro repeticoes de 100 sementes por tratamento. Na presenca de luz as sementes foram colocadas em germinador no qual se efetuou o controle fotoperiodico de 8 horas de luz e 16 horas de escuro, para cada dia. Na ausencia de luz as sementes foram semeadas e mantidas no escuro, durante todo o teste, cobrindo-se as caixas plasticas de germinacao com papel aluminio. As avaliacoes de tamanho de plântula e primeira contagem de germinacao foram efetuadas no quarto dia, e a percentagem final de germinacao no setimo dia. Observou-se que, na ausencia de luz, quanto menor a temperatura utilizada maiores foram a germinacao e o vigor (determinado pela primeira contagem de germinacao). Quando testados com luz, verificou-se, para os cultivares Elisa e Regina, que a germinacao e os maiores tamanhos de plântulas nao variam com as diferentes temperaturas, exceto para 35oC, que se mostrou desaconselhavel para as sementes de alface, por impedir a germinac ao. Conclui-se que existe influencia do genotipo sobre a qualidade fisiolo gica das sementes. A luz e um fator limitante na germinacao. Para os cultivares Elisa, Regina e Rainha de Maio, a melhor temperatura, dentre as estudadas, e de 20°C. Na presenca de luz, a germinacao e o desenvolvimento inicial ocorrem numa faixa ampla de temperatura (20°C a 30°C). A temperatura de 35°C induz a dormencia secundaria das sementes de alface.

Correlações canônicas entre caracteres morfológicos e componentes de produção em trigo de duplo propósito

The objective of this work was to identify canonical correlations between morphological traits and yield components in dual‑purpose wheat, under different cutting managements. The experiments were carried out in 2013 and 2014, under a complete block design, in a factorial arrangement with five genotypes (BRS Taruma, BRS Umbu, BRS Figueira, BRS Guatambu, and BRS 277), four cutting managements (no cuts, one cut, two cuts, and three cuts), and three replicates. The canonical groups were established between morphological traits (group 1) and yield components (group 2). In group 1, number of tillers, diameter of the main stem and of the tillers, and number of fertile tillers were evaluated; in group 2, the number of grains per spike and of spikes per square meter, the mass of grains per spike and of a thousand grains, grain yield, and hectoliter weight were evaluated. The correlation between groups 1 and 2 depends on the adopted cutting management. The diameter of the main stem (in the managements without and with one cut), tiller diameter (two cuts), and the total number of tillers and of fertile tillers per plant (three cuts) should be prioritized for selection of superior genotypes as to grain yield and hectoliter weight.