584 research outputs found

    The Use of the grassmeter as a simplified method to estimate dry matter yield on annual self-reseeding medics and clovers

    Get PDF
    BACKGROUND. The grassmeter non-destructive method was used to estimate dry matter yield (DMY) of 24 annual self-reseeding legumes. The possibility was evaluated of using the grassmeter as an alternative to conventional destructive quadrats for large field plot experiments. METHODS. The linear regressions between sward height measured by the grassmeter and DMY were analysed. Three types of regression equations were calculated: (i) ‘general’, a single equation including the three-year set of height/DMY pairs of data; (ii) ‘specific’, one regression equation for each species; (iii) ‘preliminary’, calculated from the data collected in the spring and autumn cuts of the first year. RESULTS. The ‘general’ calibration gave a satisfactory estimate of DMY (R2=0.55). The ‘specific’ calibration was particularly accurate for Trifolium brachycalicynum “Osilo” (R2=0.88), T. squarrosum “Chilivani” (R2=0.81) and Medicago polymorpha “Circle Valley” (R2=0.81), but not for M. rugosa “Sapo” (R2=0.22) and “Paraponto” (R2=0.26). The ‘preliminary’ calibration, which was based only on the destructive assessment of DMY at the first cut, provided reliable estimates of DMY until the sward conditions, namely cover rate and weeds, were comparable to those of the calibration period. The coefficient of variation of the DMY estimate based on the grassmeter ‘general’ calibration was about 10% lower than that of the DMY measured with conventional quadrats. CONCLUSIONS. Results suggest that the grassmeter could effectively replace destructive measurements for estimating the DMY of annual self-reseeding legumes, thus reducing labour requirements and number of samples to be processed, or increasing, when needed, the number of accessions to compare and hence the inference of the experiment

    Microgravity-Enhanced Stem Cell Selection

    Get PDF
    Stem cells, both embryonic and adult, promise to revolutionize the practice of medicine in the future. In order to realize this potential, a number of hurdles must be overcome. Most importantly, the signaling mechanisms necessary to control the differentiation of stem cells into tissues of interest remain to be elucidated, and much of the present research on stem cells is focused on this goal. Nevertheless, it will also be essential to achieve large-scale expansion and, in many cases, assemble cells in 3D as transplantable tissues. To this end, microgravity analog bioreactors can play a significant role. Microgravity bioreactors were originally conceived as a tool to study the cellular responses to microgravity. However, the technology can address some of the shortcomings of conventional cell culture systems; namely, the deficiency of mass transport in static culture and high mechanical shear forces in stirred systems. Unexpectedly, the conditions created in the vessel were ideal for 3D cell culture. Recently, investigators have demonstrated the capability of the microgravity bioreactors to expand hematopoietic stem cells compared to static culture, and facilitate the differentiation of umbilical cord stem cells into 3D liver aggregates. Stem cells are capable of differentiating into functional cells. However, there are no reliable methods to induce the stem cells to form specific cells or to gain enough cells for transplantation, which limits their application in clinical therapy. The aim of this study is to select the best experimental setup to reach high proliferation levels by culturing these cells in a microgravity-based bioreactor. In typical cell culture, the cells sediment to the bottom surface of their container and propagate as a one-cell-layer sheet. Prevention of such sedimentation affords the freedom for self-assembly and the propagation of 3D tissue arrays. Suspension of cells is easily achievable using stirred technologies. Unfortunately, in conventional bioreactors, stirring invokes deleterious forces that disrupt cell aggregation and results in cell death. First-generation rotating bioreactors provided rotation on the horizontal axis, which resulted in the suspension of cells without stirring, thus providing a suitable environment to propagate cells without sedimentation to a surface. The rotating wall bioreactors did not provide a way to remove air bubbles that were causing shear and disrupting 3D cultures. Johnson Space Center successfully engineered the hydrofocusing bioreactor (HFB) that resolved the problem of removing the air bubbles from the fluid medium of NASA's rotating-wall space bioreactors. The HFB uses the principle of hydrodynamic focusing that simultaneously produces a low-shear fluid culture environment and a variable hydrofocusing force that can control the movement, location, and removal of suspended cells, tissues, and air bubbles from the bioreactor. The HFB is a rotating, domeshaped cell culture vessel with a centrally located sampling port and an internal viscous spinner. The vessel and spinner can rotate at different speeds either in the same or opposite directions. Rotation of the vessel and viscous interaction at the spinner generate a hydrofocusing force. Adjusting the differential rotation rate between vessel and spinner controls the magnitude of the force

    Methods for Stem Cell Production and Therapy

    Get PDF
    The present invention relates to methods for rapidly expanding a stem cell population with or without culture supplements in simulated microgravity conditions. The present invention relates to methods for rapidly increasing the life span of stem cell populations without culture supplements in simulated microgravity conditions. The present invention also relates to methods for increasing the sensitivity of cancer stem cells to chemotherapeutic agents by culturing the cancer stem cells under microgravity conditions and in the presence of omega-3 fatty acids. The methods of the present invention can also be used to proliferate cancer cells by culturing them in the presence of omega-3 fatty acids. The present invention also relates to methods for testing the sensitivity of cancer cells and cancer stem cells to chemotherapeutic agents by culturing the cancer cells and cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce tissue for use in transplantation by culturing stem cells or cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce cellular factors and growth factors by culturing stem cells or cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce cellular factors and growth factors to promote differentiation of cancer stem cells under microgravity conditions

    Epigenetic Information and Estrogen Receptor Alpha Expression in Breast Cancer

    Get PDF
    Learning ObjectivesAfter completing this course, the reader will be able to: Describe the role of epigenetic information in the regulation of gene expression and in the development of cancer.Explain the important role of estrogen receptor expression in breast cancer as a prognostic marker and predictive factor of response to endocrine therapy.Evaluate the current and potential role that the comprehension of the molecular biology of a tumor may have in finding a new therapeutic approach in cancer treatment.Access and take the CME test online and receive 1 AMA PRA category 1 credit at CME.TheOncologist.co

    On the Fly Orchestration of Unikernels: Tuning and Performance Evaluation of Virtual Infrastructure Managers

    Full text link
    Network operators are facing significant challenges meeting the demand for more bandwidth, agile infrastructures, innovative services, while keeping costs low. Network Functions Virtualization (NFV) and Cloud Computing are emerging as key trends of 5G network architectures, providing flexibility, fast instantiation times, support of Commercial Off The Shelf hardware and significant cost savings. NFV leverages Cloud Computing principles to move the data-plane network functions from expensive, closed and proprietary hardware to the so-called Virtual Network Functions (VNFs). In this paper we deal with the management of virtual computing resources (Unikernels) for the execution of VNFs. This functionality is performed by the Virtual Infrastructure Manager (VIM) in the NFV MANagement and Orchestration (MANO) reference architecture. We discuss the instantiation process of virtual resources and propose a generic reference model, starting from the analysis of three open source VIMs, namely OpenStack, Nomad and OpenVIM. We improve the aforementioned VIMs introducing the support for special-purpose Unikernels and aiming at reducing the duration of the instantiation process. We evaluate some performance aspects of the VIMs, considering both stock and tuned versions. The VIM extensions and performance evaluation tools are available under a liberal open source licence

    Expression of CD52 in peripheral T-cell lymphoma.

    Get PDF
    open5noPeripheral T-cell lymphoma unspecified (PTCL/U) is a rare tumor characterized by poor treatment response and a dismal prognosis. We studied CD52 expression in 97 PTCL/U cases by immunohistochemistry on tissue-microarrays. Furthermore, CD52 gene expression was studied in 28 cases for which RNA was available. We found that CD52 is expressed in approximately 40% of PTCLs/U at the same level as in normal T-lymphocytes. Although other factors may play a role in the in vivo response to alemtuzumab, an anti-CD52 monoclonal antibody, the estimation of CD52 expression may provide a rationale for the selection of patients with a higher probability of treatment response.openPiccaluga PP; Agostinelli C; Righi S; Zinzani PL; Pileri SA.Piccaluga PP; Agostinelli C; Righi S; Zinzani PL; Pileri SA

    How does the human RUNX3 gene induce apoptosis in gastric cancer? Latest data, reflections and reactions.

    Get PDF
    RUNX3 is the oldest known gene in the RUNX family. Data have demonstrated its function to be thoroughly involved the neurogenesis of the dorsal root ganglia, T-cell differentiation and tumorigenesis of gastric epithelium. As a TGF-beta target, RUNX3 protein is believed to be involved in TGF-beta-mediated tumor suppressor pathway; however, little is known about its role in apoptosis. According to recent data reported by Yamamura et al., (J Biol Chem 2006; 281:5267-76), RUNX3 interacts with FoxO3a/FKHRL1 expressed in gastric cancer cells to activate Bim and induce apoptosis. The cooperation between RUNX3 and the PI3K/Akt signaling pathway component FoxO3a/FKHRL1 suggests the putative role of RUNX3 in the homoeostasis of gastric cells and in stomach cancer control. Here we discuss recent breakthroughs in our understanding of the mechanisms of RUNX3 in gastric malignancy and comment on possible future trends and perspectives

    Epi-mucosa fixation and autologous platelet-rich fibrin treatment in medication-related osteonecrosis of the jaw

    Get PDF
    Medication-related osteonecrosis of the jaw (MRONJ) frequently affects patients after treatments with bisphosphonates or denosumab, especially with high doses in patients with bone osteoporosis, neoplastic metastases, or possibly anti-angiogenic treatment for cancer. The aim of this article was to show a new treatment planning for stage 2 and stage 3 MRONJ using platelet-rich fibrin (PRF) at the surgical field to enhance healing in association with a new epi-mucosal fixation technique to prevent or treat mandibular fracture. Two cases were treated by epi-mucosa fixation and autologous PRF use for prevention of mandibular fracture risks related to necrotic bone resection or a narrow fracture reduction. Both cases were successfully treated by this new technique of epi-mucosa fixation combined with autologous PRF and achieved good results and good quality of life. Ability to wear prosthesis with good mastication in the absence of side effect such as infection, plate and screw mobilization, pain, and other disabilities or extension of necrosis was reported. After surgical removal of necrotic bone, no infection was detected without any extension of the necrosis
    corecore