Plant cell commitment

There is compelling evidence for determination in the development of plants (6-10). During embryogenesis, root and shoot meristems arise from a common cell, the zygote. These structures consist of self-renewing populations of cells committed to form specific structures (11). This commitment is evident when small explants containing apical meristems are cultured in isolation. Explants from shoot tips form shoots in culture, whereas explants from root tips form roots in culture (12-15). 

Much of the difficulty in drawing more-exact conclusions about wall biosynthesis arises from the fact that most of the work thus far has involved the individual, biosynthetic steps. Only the group of workers led by Albersheim36-63 has made a committed attempt to project a universal model for primary cell-wall structures in higher plants (see Section IX) on the basis of characterization of individual wall-components, and this model is by no means undisputed. Thus, workers in the biosynthetic field have found themselves studying the synthesis of natural products of currently unknown, or at least unconfirmed, structure. 

The cells of most multicellular organisms are differentiated both in structure and function. This differentiation is most highly developed in plants and animals, where there is profusion of cell types, each performing a different function within the collective whole of the organism. Generally, once a cell has become differentiated to perform a specific activity it is rarely able to change its function it is committed until it dies. 

Monoclonal Antibodies from Murine Hybridomas. Murine hybridomas are hybrid cells formed by the fusion of a mouse cancer cell with lymphocytes committed to the secretion of antibodies. The lymphocytes are obtained from the spleens of mice immunized with antigens of interest, e.g. extracellular glycoproteins from a fungal plant pathogen, and under normal circumstances would produce antibodies, but would be unable to divide. Fusion with cancer cells yields hybrids that continue to divide, as well as secrete antibodies. Thus, from a population of lymphocytes from the spleen of an immunized mouse it is possible to generate numerous clones of hybridomas and each clone will yield a single antibody, i.e. monoclonal antibodies. 

The Facility Supervisor and Hot Cell Operators are qualification positions requiring successful completion of a formal training program before an individual Is allowed to operate specific HCF equipment and/or controls unsupervised. Proficiency for the qualified positions is demonstrated by minimum acceptable scores on written tests and by observation of the individual s operating skill with manipulators, production process equipment, and plant safety equipment and safety systems. Qualification also requires demonstrated adherence to conduct of operations principles, ability to follow procedures, and commitment to cultivating an environment of teamwork and continuous improvement. Staff contributions to improvement of procedures and processes are actively encouraged as a way to enhance the safety and work culture. 

Considerable commitment to fuel cell technology has been made in the United States experience has been gained of well over 13,000-hr operation of stable cells, with 40,000-hr cells underway. A 635-MW coal-fired power plant consisting of 96 cells of 4.7 MW (dc) each is envisaged. Although noble metal electrocatalysts can be avoided in molten salt fuel cells, consider-... 

---