Abstract This research was conducted for the purpose to evaluate the contribution Giant petrels and Brown skuas nestings in the formation of ornithogenic soils by the phosphatization process in Harmony Point, Maritime Antarctic. Ten nests were selected to collect topsoil samples (0-20 cm), from 0 m up to 20 m away, with regular spacing of 2 m. The analysis of the samples included the physical, chemical, mineralogical and geochemical analyzes. Phosphate minerals were identified. The presence of high content of some trace elements, such as Zn, Cu and Sr is associated with the bird’s excrements. Total-P and bioavailable-P recorded higher levels. This result demonstrates the importance of the time factor in the bird’s nesting, as well as in the development of the soil in these soil-forming environment. Phosphatization in these areas is not restricted to the specific location of the nest, since high values of P have been identified at distances between 8 and 12 m, from de nest’s top. This suggests the transport of P rich solutions and phosphatized material along fractures by the freeze-thaw cycles, contributing to increase the geographical expression of this phenomenon in this ice-free area, consequently the development of soils and the establishment of vegetation.

Abstract This article carried out the first scientometric and spatial analysis of Brazilian scientific production on Antarctic soils and permafrost, based on all publications available from the Scopus and Web of Science databases. Information on co-authorship, citation, research topics, and sampling sites was used to understand the social and theoretical structure as well as the spatial dynamics of this research field in Brazil over the last 25 years. We highlight that Brazil is presently, the main country to study the soils and permafrost of Maritime Antarctica, in addition to having an international robust and prolific production, with high impact on the literature, and widely distributed throughout the studied region. It was also possible to identify potential future international partners, new research locations and strategic research themes. databases coauthorship, coauthorship co authorship, authorship co-authorship citation topics 2 years presently Antarctica literature region partners themes

Abstract Sulfurization is a pedogenic process that involves pyrite oxidation and strong soil acidification, accounting for the formation of acid sulfate soils. In Antarctica, acid sulfate soils are related to specific parent materials, such as sulfide-bearing andesites in Maritime Antarctica and pyritized sedimentary rocks in James Ross Archipelago. The hypothesis is that the acid sulfate soils of these regions vary according with a climate gradient. The reviewing of current data showed that the acid sulfate soils of warmer and wetter Maritime Antarctica have a greater weathering degree, higher acidity, leaching, phosphorus adsorption capacity, structural development, and well-crystallized iron oxides and kaolinite formation. On the other hand, the sulfurization at the drier region of James Ross Archipelago is counterbalanced by the semiaridity, resulting in lower acidity and higher base contents combined with little morphological and mineralogical evolution besides presence of weatherable minerals in the clay fraction. The sulfurization process interplays with other pedogenic processes, such as the phosphatization in Maritime Antarctica and salinization in James Ross Archipelago. Higher temperatures and soil moisture enhance the pedogenesis, showing that even the Antarctic sulfate soils, which originated from specific parent materials, have their development and characteristics controlled by a clear climatic gradient.

Abstract The majority of ornithogenic soils studied in Antarctica focus on the influence of penguins, wherever little reports evaluated the influence of flying birds on soil genesis. This study aimed to characterize the morphologic, chemic, physic, mineralogic, and micromorphologic ornithogenic soil pockets influenced by flying birds in Snow Island, Maritime Antarctica. Fifteen soil pockets were selected, described, sampled and analyzed, these sites constitute the main areas with intense long-term terrestrial biological activity in Snow Island. In order to investigate the impact of phosphatization, we compared the soil pockets with the surrounding soils and soils affected by penguins. Zone of phosphatization have a high concentration of P, K, and Ca. The XRD patterns for the clay fraction of ornithogenic soils show that phosphate minerals are the main crystalline phases (leucophosphite, minyulite, fluorapatite, and apatite). We show that even under typical periglacial conditions, sites influenced by flying birds present active chemical weathering processes. The phosphatization release exchangeable bases and accelerate mineralogical and micromorphological transformations in soils. Under the current global warming trend and expected sea-level rise, the ornithogenic environments are susceptible to accelerated erosion rates and a great part of these hotspots may be lost for the open sea.

Abstract This study characterized the physical, chemical, macro- and micromorphological soil properties from three successive marine terrace levels from Harmony Point (Nelson Island, Maritime Antarctica) in order to understand the pedological signatures of Quaternary coastal landscape evolution of Maritime Antarctica. Soils were sampled on the Late Holocene beach (current beach) and Mid Holocene marine terraces higher up, at 3, 8, and 12 m a.s.l. At the lower levels, the predominant soils were Gelorthents, whereas Haplogelepts dominate the higher terraces. Soil properties are mostly influenced by parent material and faunal activity, in which cryoclastic (thermal weathering) and phosphatization are the main soil-forming processes. Soils from the upper levels are more developed, deeper with reddish colors, granular structures and incipient formation B horizon. These horizonation features highlight that soils vary according with age of glacier-isostatic terrace uplift, representing a Quaternary soil chronosequence. All marine terrace levels are Ornithogenic soils, at varying degrees. However, the presence of old bird nesting sites for long periods led to formation of phosphatic horizons, stable Fe-phosphate minerals and abundant vegetation in the highest terraces of this part of Maritime Antarctica.

ABSTRACT The profile of volatile organic compounds, the glandular and non-glandular trichomes of Plectranthus ornatus, obtained by in vitro cultivation, was evaluated in plants grown in Murashide and Skoog medium supplemented with benylaminopurine at 4.5, 9.0, and 18.0 µM + naphthaleneacetic acid at 5.37 µM, kinetin at 4.7, 9.3 and 18.5 µM + naphthaleneacetic acid (5.37 µM) or Murashide and Skoog 0 medium (as a control). Scanning Electron Microscopy was performed on samples of the third leaf node of the 90 days old plants obtained from treatment with 4.5 or 9.0 µM benylaminopurine, and 4.7 or 9.3 µM kinetin. Headspace Solid Phase Micro-Extraction of the 30, 60 and 90 days old in vitro plants permitted to determinate by GC/MS the composition comprised of 62 compounds. The data were analyzed using Principal Component Analysis and Hierarchical Clustering Analysis and, the major constituents of these oils after treatment and aging were monoterpenes and sesquiterpenes. Morphoanatomical analysis of trichomes, by Scanning Electron Microscopy, enabled the identification of non-glandular trichomes and four types of glandular trichomes, which comprised capitate and peltate glandular trichomes that were distributed on both sides of the leaf. We observed that the regulators influenced qualitative and quantitative profiles of the volatile organic compounds and the number and distribution of hairs on the leaf surface.

Food security has become a major concern of the world population and this is even more prominence in polluted areas. This study aimed to evaluate microbiological and toxic elements content of local food itens from Santo Amaro, Bahia. The determination of lead, cadmium, Escherichia coli (E. coli) and total coliform were carried out in coriander, cassava, okra, chicken muscle/liver, fish muscle and eggs. The population of total coliform and E. coli were estimated by the express count method using plates EC (AOAC 991.14) and accounting of colonies by colony counter. For toxic elements determination samples were digested using HNO3 and H2O2 following EPA 200.3 using a digester block with cold fingers. The determination of lead and cadmium was performed by inductively coupled plasma optical emission spectrometery (ICP OES). The mean total coliform has ranged from < 1 to 4.5 log CFU g-1. Coriander presented higher mean total coliform (4.5 log CFU g-1) and E. coli was higher than recommended levels. The range of toxic elements revealed higher concentrations of lead in chicken muscle (1.25-11.58 mg kg-1) and cadmium in eggs (0.45-1.06 mg kg-1). Finally, the risk to the inhabitants of Santo Amaro was evident and reinforces the importance of effective actions of local authorities.

The objective of this work is to develop a film thickness and velocity measurement technique using laser intensity measurement in liquid film flow. This technique was developed for annular flow studies, but it has been scarcely used due to the equipment's complexity, as compared with other techniques. The laser technique uses the reflection of the laser beam in water interface and the attenuation of its intensity to determine the interface position. Thus, the relation between intensity and thickness must be obtained by calibration. A theoretical model was proposed for the optical phenomena present in the film thickness measurement and its results were compared with experimental results using a planar mirror. A controlled experiment was conducted using one-dimensional waves in a short channel where the wave frequencies were varied by changing the vibrator's frequency and the film thickness was modified by changing the liquid volume. The reference film thickness was obtained by the analysis of photographic data taken through the transparent channel walls, allowing the comparison to the results from the laser technique. The experimental results for the film thickness presented a good agreement with the reference thickness from photographic data. The interface wave propagation velocities were measured with good accuracy, showing good agreement with the theoretical data.