11 research outputs found

    Carbon pool ratios as scientific support to field morphology in the differentiation of dark subsurface soil horizons

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    In soil surveys, it is usual to find profiles with an uncommon disposition of horizons. Dark horizons in depth might be either the consequence of erosion and redeposition of soil materials from upslope or an indication of the podzolization process, which forms a spodic horizon. Few laboratory analyses are known to characterize dark subsurface horizons which could allow for the differentiation of spodic from buried A horizons. Some researchers propose C-humic and C-fulvic acid fraction ratios and forms of carbon to analyze characteristics of these horizons. Therefore, this research aimed to characterize dark subsurface horizons found in soils under a Eucalyptus minimum tillage system in the state of Rio Grande do Sul, Brazil, and to relate soil organic carbon to landscape features in toposequences. The characterization was performed by using the following ratios: humic acid and fulvic acid fractions (Cha/Cfa); pyrophosphate extractable-C and organic carbon (Cp/OC); fulvic acid fraction and pyrophosphate extractable-C (Cfa/Cp), and fulvic acid fraction and organic carbon (Cfa/OC). Soil organic carbon was related to slope gradient and Geomorphons in a Geographic Information System (GIS). None of the horizons analyzed met the criteria required for spodic horizon classification, where Cha/Cfa < 0.50, Cfa/OC < 0.30, and the ratio Cp/OC ≥ 0.50 simultaneously with Cfa/Cp ≥ 0.50. A relationship was found between landscape features and soil organic carbon content. The methodology proved to be satisfactory for providing scientific support to field morphology classification of dark subsurface horizons, specifically in the case where they could be misinterpreted as spodic horizons

    A Quality-by-Design Approach to Risk Reduction and Optimization for Human Embryonic Stem Cell Cryopreservation Processes

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    Final publication is available from Mary Ann Liebert, Inc., publishers: https://doi.org/10.1089/ten.tec.2013.0595.It is well documented that cryopreservation and resuscitation of human embryonic stem cells (hESCs) is complex and ill-defined, and often suffers poor cell recovery and increased levels of undesirable cell differentiation. In this study we have applied Quality-by-Design (QbD) concepts to the critical processes of slow-freeze cryopreservation and resuscitation of hESC colony cultures. Optimized subprocesses were linked together to deliver a controlled complete process. We have demonstrated a rapid, high-throughput, and stable system for measurement of cell adherence and viability as robust markers of in-process and postrecovery cell state. We observed that measurement of adherence and viability of adhered cells at 1h postseeding was predictive of cell proliferative ability up to 96h in this system. Application of factorial design defined the operating spaces for cryopreservation and resuscitation, critically linking the performance of these two processes. Optimization of both processes resulted in enhanced reattachment and post-thaw viability, resulting in substantially greater recovery of cryopreserved, pluripotent cell colonies. This study demonstrates the importance of QbD concepts and tools for rapid, robust, and low-risk process design that can inform manufacturing controls and logistics

    Proteomic Approaches for Studying the Phases of Wound Healing

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    © 2009, Springer Berlin Heidelberg. Proteome level information is necessary to understand the function of specific cell types and their roles in health and disease. Proteomics is a rapidly developing field with a wide range of applications in wound healing. The ability to use proteomics to assess the wound healing process would have many benefits, including earlier evidence of healing and better understanding of how different treatments affect the wound at the protein level. The basis of what is known about the chronic wound proteome is based on results from a broad collection of studies utilizing a number of different proteomic techniques on fluids and tissues from wounds with different etiologies. The identification of biomarkers associated with healing or delayed healing in chronic wounds could have great significance in the use of current treatments, as well as in the development of new therapeutic interventions

    Polyomaviruses and Human Diseases

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