29 research outputs found

    Sustainable farming with native rocks: the transition without revolution.

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    The development process which humanity passed through favored a series of conquests, reflected in the better quality of life and longevity, however, it also provoked upsets and severe transformation in the environment and in the human food security. Such process is driving the ecosystems to be homogeneous, and, therefore,the nutrients� supply, via nourishment. To change this panorama, the present work discusses the gains of incorporating the stonemeal technique as a strategic alternative to give back the essential fertile characteristics to the soils. This technology has the function of facilitating the rejuvenation of the soils and increasing the availability of the necessary nutrients to the full development of the plants which is a basic input for the proliferation of life in all its dimensions

    A comprehensive overview of radioguided surgery using gamma detection probe technology

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    The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology

    Rainfall chemistry composition in two ecosystems in the northeastern Brazilian Amazon (Amapa State)

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    The rainfall chemical composition in two Amazonian ecosystems, a "terra firme" forest (dense tropical rain forest) and the "cerrado" (savanna) are presented. Both areas are located in the northeast Brazilian Amazon (Amapa State). This study evaluated the statistical differences in the rainfall chemistry, as well as the deposition through rainfall, for each ecosystem. The chemical species evaluated in the rainwater were Na+, K+, Mg2+, Ca2+, NH4+, Cl-, NO3-, SO42-, Fe3+, Al3+, Zn2+, and Mn2+ for both ecosystems. Factor analysis for the terra fume ecosystem indicated that there is a significant difference between the dry and wet periods in the rainfall chemical composition, indicating a biomass-burning signature (K+ in association with Zn2+. High deposition of solutes, except for Mn2+ and Cl+, was also observed during the dry period. Comparison between the terra fume and cerrado rainfall chemistry showed statistical differences in concentration for the marine species (Nac and CU and for the soil dust species (Al3+, Fe3+, and Mn2+. The sea-salt and biogenic sources of chemical species in terra fume forest rainwater are equally important. The site nearer to the sea (cerrado) has rainfall chemistry dominated by species having marine origins. The terra firme forest also has rainfall chemistry dominated by marine origin species, although the biogenic and soil dust origin species are highly significant at this site. Also in the terra firme a biomass-burning signature was observed. The amount of sea salt deposited was more than 50% larger in the cerrado owing to its proximity to the shore.105D23288952890

    Mercury fluxes in a natural forested Amazonian catchment (Serra do Navio, Amapa State, Brazil)

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    Mercury (I-Ig total) fluxes were calculated for rainwater, throughfall and stream water in a small catchment located in the northeastern region of the Brazilian Amazon (Serra do Navio, Amapa State), whose upper part is covered by a natural rainforest and lower part was altered due to deforestation and activities related to manganese mining. The catchment area is 200 km from the nearest gold mining (garimpo). Minimum and maximum Hg concentrations were measured monthly from October 1996 to September 1997 and were 3.5-23.4 ng l(-1) for rainwater, 16.5-82.7 ng l(-1) for throughfall (March-August 1997) and 1.2-6.1 and 4.2-18.8 ng l(-1) for stream water, in natural and disturbed areas, respectively. In the natural area, the inputs were 18.2 mu g m(-2) year(-1) in rainwater and 72 mu g m(-2) year(-1) in throughfall. This enrichment was attributed to dry deposition. The stream output of 2.9 mu g m(-2) year(-1) indicates that Hg is being recycled within the forest as other chemical species or is being retained by the soil system, as confirmed by the cumulative Hg burden in the 0-10 cm surface layer, which was 36 480 mu g m When the disturbed area of the catchment was included, the stream output was 9.3 mu g m(-2), clearly indicating the impact of the deforestation of the lower part of the basin on the release of mercury. The Hg burden in the disturbed area was 7560 mu g m(-2) for the 0-10 cm surface layer. (C) 2000 Elsevier Science B.V. All rights reserved.2604169920121

    Podzolization as a deferralitization process: a study of an Acrisol-Podzol sequence derived from Palaeozoic sandstones in the northern upper Amazon Basin

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    Morphological, geochemical and mineralogical studies were carried out in a representative soil catena of the low-elevation plateaux of the upper Amazon Basin to interpret the steps and mechanisms involved in the podzolization of low-activity clay soils. The soils are derived from Palaeozoic sandstones. They consist of Hydromorphic Podzols under tree savannah in the depressions of the plateaux and predominantly of Acrisols covered by evergreen forest elsewhere. Incipient podzolization in the uppermost Acrisols is related to the formation of organic-rich A and Bhs horizons slightly depleted in fine-size particles by both mechanical particle transfer and weathering. Weathering of secondary minerals by organic acids and formation of organo-metallic complexes act simultaneously over short distances. Their vertical transfer is limited. Selective dissolution of aluminous goethite, then gibbsite and finally kaolinite favour the preferential cheluviation of first Fe and secondly Al. The relatively small amount of organo-metallic complexes produced is related to the quartzitic parent materials, and the predominance of Al over Fe in the spodic horizons is due to the importance of gibbsite in these low-activity clay soils. Morphologically well-expressed podzols occur in strongly iron-depleted topsoils of the depression. Mechanical transfer and weathering of gibbsite and kaolinite by organic acids is enhanced and leads to residual accumulation of sands. Organo-metallic complexes are translocated in strongly permeable sandy horizons and impregnate at depth the macro-voids of embedded soil and saprolite materials to form the spodic Bs and 2BCs horizons. Mechanical transfer of black particulate organic compounds devoid of metals has occurred later within the sandy horizons of the podzols. Their vertical transfer has formed well-differentiated A and Bh horizons. Their lateral removal by groundwater favours the development of an albic E horizon. In an open and waterlogged environment, the general trend is therefore towards the removal of all the metals that have initially accumulated as a response to the ferralitization process and have temporarily been sequestrated in organic complexes in previous stages of soil podzolization

    Robot-Assisted Paravertebral Schwannoma Resection

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    Robot-assisted thoracic surgery is at the forefront of minimally invasive approaches for resection of various intrathoracic benign and malignant tumors. The robotic approach is particularly suitable for solitary paravertebral schwannomas along the thoracic spine, lacking an intraspinal component, that are typically treated with complete resection and carry an excellent prognosis. Here, robotic platforms have established themselves as safe, reliable, and reproducible tools in expanding the surgeon’s reach in complex tumor resections and enable junior surgeons to overcome the learning curve quicker without compromising oncologic principles or patient safety. This chapter appraises the existing literature and provides an in-depth review of the technical aspects of robot-assisted paravertebral schwannoma resection
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