Oviposition by a moth suppresses constitutive and herbivore-induced plant volatiles in maize

Plant volatiles function as important signals for herbivores, parasitoids, predators, and neighboring plants. Herbivore attack can dramatically increase plant volatile emissions in many species. However, plants do not only react to herbivore-inflicted damage, but also already start adjusting their metabolism upon egg deposition by insects. Several studies have found evidence that egg deposition itself can induce the release of volatiles, but little is known about the effects of oviposition on the volatiles released in response to subsequent herbivory. To study this we measured the effect of oviposition by Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) moths on constitutive and herbivore-induced volatiles in maize (Zea mays L.). Results demonstrate that egg deposition reduces the constitutive emission of volatiles and suppresses the typical burst of inducible volatiles following mechanical damage and application of caterpillar regurgitant, a treatment that mimics herbivory. We discuss the possible mechanisms responsible for reducing the plant`s signaling capacity triggered by S. frugiperda oviposition and how suppression of volatile organic compounds can influence the interaction between the plant, the herbivore, and other organisms in its environment. Future studies should consider oviposition as a potential modulator of plant responses to insect herbivores.

Evaluation of gamma-radiation on green tea odor volatiles

The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds. (C) 2010 Elsevier Ltd. All rights reserved.

Determination of volatiles produced during radiation processing in Laurus cinnamomum

In order to protect food from pathogenic microorganisms as well as increase its shelf-life, while keeping sensorial properties (e.g., odor and taste), which are important properties required by spice buyers, it is necessary to analyze volatile formation from irradiation of medicinal and food herbs. Possible changes in the odor of these herbs are evaluated by characterizing different radiation doses and effects on sensorial properties, in order to allow better application of the irradiation technology. The aim of the present study was to analyze volatile formation on cinnamon (Laurus cinnamomum) samples after gamma irradiation. These samples were irradiated into plastic packages using a (60)Co facility. Radiation doses applied were 0, 5, 10, 15, 20 and 25 kGy. For the analysis of the samples, solid-phase microextraction (SPME) was applied, while for the analysis of volatile compounds, CG/MS. Spice irradiation showed the highest decrease in volatile compounds. For L. cinnamomum, the irradiation decreased volatile compounds by nearly 56% and 89.5%, respectively, comparing to volatile from a sample which had not been previously irradiated. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.

Contaminantes voláteis provenientes de embalagens plásticas: desenvolvimento e validação de métodos analíticos

Plastic packaging materials intended for use in food packaging is an area of great interest from the scientific and economic point of view due to the irreversible internationalization and globalization process of food products. Nevertheless, a debate related to food safety aspects has emerged within the scientific community. Therefore, the development of analytical methods that allow identifying and quantifying chemical substances of toxicological potential in the packaging is considered essential. This article focuses on the main analytical methods, including validation parameters, as well as extraction and quantification techniques for determination of volatile organic compounds from food packaging materials.

Comparative study of the hygienic behavior of Carniolan and Africanized honey bees directed towards grouped versus isolated dead brood cells

In Apis mellifera, hygienic behavior involves recognition and removal of sick, damaged or dead brood from capped cells. We investigated whether bees react in the same way to grouped versus isolated damaged capped brood cells. Three colonies of wild-type Africanized honey bees and three colonies of Carniolan honey bees were used for this investigation. Capped worker brood cells aged 12 to 14 days old were perforated with the pin-killing method. After making holes in the brood cells, the combs were placed back into the hives; 24 h later the number of cleaned cells was recorded in areas with pin-killed and control brood cells. Four repetitions were made in each colony. Isolated cells were more frequently cleaned than grouped cells, though variance analysis showed no significant difference (P = 0.1421). Carniolan bees also were somewhat, though not significantly more hygienic than Africanized honey bees (P = 0.0840). We conclude that honey bees can detect and remove both isolated and grouped dead brood. The tendency towards greater hygienic efficiency directed towards grouped pin-killed brood may be a consequence of a greater concentration of volatiles emanating from the wounds in the dead pupae.

Porous alumina-spinel ceramics for high temperature applications

In order to reduce energy costs, high-temperature insulation porous refractory ceramics have been subjected to increasing demands. Among the techniques used to produce these materials (such as the addition of foaming agents and organic compounds), the pore generation via phase transformation presents key aspects, such as easy processing and the absence of toxic volatiles. In this study, this technique was applied to produce porous ceramics by decomposing an aluminum magnesium hydro-carbonate known as hydrotalcite (Mg(6)Al(2)(CO(3))(OH)(16)center dot 4H(2)O). It was found out that by using this complex compound, a large fraction of pores can be generated and kept at high temperatures (above 1300 degrees C) due to the in situ formation of spinel-like phases (MgAl(2)O(4)). (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Physical-chemical and operational performance of an anaerobic baffled reactor (ABR) treating swine wastewater

Since hog raising concentrates a huge amount of swine manure in small areas, it is considered by the environmental government organizations to be one of the most potentially pollutant activities. Therefore the main objective of this research was to evaluate by operational criteria and removal efficiency, the performance of a Anaerobic Baffled Reactor (ABR), working as a biological pre-treatment of swine culture effluents. The physical-chemical analyses carried out were: total COD, BOD(5), total solids (TS), fix (TFS) and volatiles (TVS), temperature, pH, total Kjeldahl nitrogen, phosphorus, total acidity and alkalinity. The ABR unit worked with an average efficiency of 65.2 and 76.2%, respectively, concerning total COD and BOD(5), with a hydraulic retention time (HRT) about 15 hours. The results for volumetric organic loading rate (VOLR), organic loading rate (OLR) and hydraulic loading rate (HLR) were: 4.46 kg BOD m(-3) day(-1); 1.81 kg BOD(5) kg TVS(-1) day(-1) and 1.57 m(3) m(-3) day(-1), respectively. The average efficiency of the whole treatment system for total COD and BOD(5) removal were 66.5 and 77.8%, showing an adequate performance in removing die organic matter from swine wastewater.

Reaction rate and product morphology in carbon composite iron ore pellets with and without Portland cement

The aim of this work is to study the reaction rate and the morphology of intermediate reaction products during iron ore reduction when iron ore and carbonaceous materials are agglomerated together with or without Portland cement. The reaction was performed at high temperatures, and used small size samples in order to minimise heat transfer constraints. Coke breeze and pure graphite were the carbonaceous materials employed. Portland cement was applied as a binder, and pellet diameters were in the range 5.6-6.5 mm. The experimental technique involved the measurement of the pellet weight loss, as well as the interruption of the reaction at different stages, in order to submit the partially reduced pellet to scanning electron microscopy. The experimental temperature was in the range 1423-1623 K, and the total reaction time varied from 240 to 1200 s. It was observed that above 1523 K the formation of liquid slag occurred inside the pellets, which partially dissolved iron oxides. The apparent activation energies obtained were 255 kJ mol(-1) for coke breeze containing pellets, and 230 kJ mol(-1) for those pellets containing graphite. It was possible to avoid heat transfer control of the reaction rate up to 1523 K by employing small composite pellets.

Effect of the Gamma Radiation Dose Rate on Psychrotrophic Bacteria, Thiobarbituric Acid Reactive Substances, and Sensory Characteristics of Mechanically Deboned Chicken Meat

Frozen samples of mechanically deboned chicken meat (MDCM) with skin were irradiated with gamma radiation doses of 0.0 kGy (control) and 3 kGy at 2 different radiation dose rates: 0.32 kGy/h (3 kGy) and 4.04 kGy/h (3 kGy). Batches of irradiated and control samples were evaluated during 11 d of refrigerated (2 +/- 1 degrees C) storage for the following parameters: total psychrotrophic bacteria count, thiobarbituric acid reactive substances (TBARS), evaluation of objective color (L*, a*, and b*) and a sensory evaluation (irradiated odor, oxidized odor, pink and brown colors). No statistical difference (P > 0.05) was found amongst the TBARS values obtained for the MDCM samples irradiated with dose rates of 0.32 and 4.04 kGy/h. There was a significant increase (P < 0.05) in the psychrotrophic bacterial count as from the 7th day of refrigerated storage, for the MDCM samples irradiated at the dose rate of 4.04 kGy/h. With respect to the attribute of oxidized odor, the samples irradiated with a dose rate of 0.32 kGy/h showed a stronger intensity and were significantly different (P < 0.05) from the sample irradiated with a dose rate of 4.04 kGy/h on days 0 and 2 of refrigerated storage. Irradiation with a dose rate of 4.04 kGy/h (3 kGy) was shown to be the best condition for the processing of MDCM according to the evaluation of all the variables, under the conditions of this study. Practical Application The results obtained for the application of different dose rates of ionizing radiation to mechanically deboned chicken meat will provide the food industry with information concerning the definition of the best processing conditions to maximize the sensory and food quality.

Transcript profiling of papaya fruit reveals differentially expressed genes associated with fruit ripening

Papaya (Carica papaya L) fruit has a short shelf life due to fast ripening induced by ethylene, but little is known about the genetic control of ripening and attributes of fruit quality. Therefore, we identified ripening-related genes affected by ethylene using cDNA-AFLP (Amplified Fragment Length Polymorphism of cDNA). Transcript profiling of non-induced and ethylene-induced fruit samples was performed, and 71 differentially expressed genes were identified. Among those genes some involved in ethylene biosynthesis, regulation of transcription, and stress responses or plant defence were found (heat shock proteins, polygalacturonase-inhibiting protein, and acyl-CoA oxidases). Several transcription factors were isolated, and except for a 14-3-3 protein, an AP2 domain-containing factor, a salt-tolerant zinc finger protein, and a suppressor of PhyA-105 1, most of them were negatively affected by ethylene, including fragments of transcripts similar to VRN1, and ethylene responsive factors (ERF). With respect to fruit quality, genes related to cell wall structure or metabolism, volatiles or pigment precursors, and vitamin biosynthesis were also found. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Analyses of the Headspace Volatile Constituents of Aerial Parts (leaves and stems), Flowers and Fruits of Bidens gardneri Bak. and Bidens sulphurea (Cav.) Sch.Bip. Using Solid-Phase Microextraction

The present study describes the volatile composition of aerial parts (leaves and stems), flowers and fruits from Bidens gardneri and Bidens sulphurea. The first species is widely distributed in Pantanal (Brazil) and is a traditional medicinal plant, while the second species is widely distributed throughout Brazil. In all analyses, observed were constituents like bicycloelemene, alpha-copaene, beta-caryophyllene, germacrene D, bicyclogermacrene and others. However, some compounds were identified only in one part of the plants analyzed. These results indicated sonic differences in the composition of the plants studied and they were in agreement with data of literature.

The extreme physical properties of the CoRoT-7b super-Earth

The search for rocky exoplanets plays an important role in our quest for extra-terrestrial life. Here, we discuss the extreme physical properties possible for the first characterised rocky super-Earth, CoRoT-7b (R(pl) = 1.58 +/- 0.10 R(Earth), M(pl) = 6.9 +/- 1.2 M(Earth)). It is extremely close to its star (a = 0.0171 AU = 4.48 R(st)), with its spin and orbital rotation likely synchronised. The comparison of its location in the (M(pl), R(pl)) plane with the predictions of planetary models for different compositions points to an Earth-like composition, even if the error bars of the measured quantities and the partial degeneracy of the models prevent a definitive conclusion. The proximity to its star provides an additional constraint on the model. It implies a high extreme-UV flux and particle wind, and the corresponding efficient erosion of the planetary atmosphere especially for volatile species including water. Consequently, we make the working hypothesis that the planet is rocky with no volatiles in its atmosphere, and derive the physical properties that result. As a consequence, the atmosphere is made of rocky vapours with a very low pressure (P <= 1.5 Pa), no cloud can be sustained, and no thermalisation of the planet is expected. The dayside is very hot (2474 +/- 71 K at the sub-stellar point) while the nightside is very cold (50-75 K). The sub-stellar point is as hot as the tungsten filament of an incandescent bulb, resulting in the melting and distillation of silicate rocks and the formation of a lava ocean. These possible features of CoRoT-7b could be common to many small and hot planets, including the recently discovered Kepler-10b. They define a new class of objects that we propose to name ""Lava-ocean planets"". (C) 2011 Elsevier Inc. All rights reserved.

The Determination of Total Hydrogen, Carbon, Nitrogen and Sulfur in Silicates, Silicate Rocks, Soils and Sediments

Determinations of the volatile elements carbon, hydrogen, sulfur and nitrogen in many geological RM, performed with the LECO CHN and SC analysers, are presented. The method allowed the determination of S in concentrations from a few % m/m to 0.001% m/m or less, of C from % m/m to 0.01% m/m and of H from % m/m to 0.004% m/m. Accuracy was usually better than the XRF method (for S). All obtained values passed the Sutarno-Steger test, which establishes that vertical bar(mean(analysed) - mean(certified))vertical bar/ S(certified) < 2, for the cases with an appropriate number of determinations (n > 10 for each element). It was possible to perform routine determination of C, H and S with the instrumentation, coupled with the determination of major and minor elements in geological materials. Determination of nitrogen could also be performed on an exploratory basis, with improvements in the method dependent on the future availability of more reference materials with reliable composition of this element.

Useful Strategies for Algal Volatile Analysis

The production of volatile organic compounds (VOC) by plants is well known. However, few scientific groups have studied VOC produced by green, brown and red algae. Headspace collection of volatiles and solid phase microextraction, as well as the traditional extraction by hydrodistillation combined with analytical chromatographic techniques (i.e., GC-MS), have significantly improved the investigation of VOC from plants and algae. The major volatile compounds found in seaweeds are hydrocarbons, terpenes, phenols, alcohols, aldehydes, ketones, esters, fatty acids and halogen or sulfur-containing compounds. This article presents an overview of VOC isolated from and identified in marine macro-algae. Focus is given to non-halogenated and non-sulfur volatile compounds, as well as strategies to analyze and identify algal VOC by GC-MS.